anvil

package: postfix

title: anvil(8)

text:
# anvil(8)

## NAME
anvil - Postfix session count and request rate control

## SYNOPSIS

```
anvil [generic Postfix daemon options]
```

## DESCRIPTION

The Postfix anvil(8) server maintains statistics about client connection counts or client request rates. This information can be used to defend against clients that hammer a server with either too many simultaneous sessions, or with too many successive requests within a configurable time interval. This server is designed to run under control by the Postfix master(8) server.

In the following text, ident specifies a (service, client) combination. The exact syntax of that information is application-dependent; the anvil(8) server does not care.

## CONNECTION COUNT/RATE CONTROL

```

```

To register a new connection send the following request to the anvil(8) server:

```
    request=connect

    ident=string
```

The anvil(8) server answers with the number of simultaneous connections and the number of connections per unit time for the (service, client) combination specified with ident:

```
    status=0

    count=number

    rate=number
```

To register a disconnect event send the following request to the anvil(8) server:

```
    request=disconnect

    ident=string
```

The anvil(8) server replies with:

```
    status=0
```

## MESSAGE RATE CONTROL

```

```

To register a message delivery request send the following request to the anvil(8) server:

```
    request=message

    ident=string
```

The anvil(8) server answers with the number of message delivery requests per unit time for the (service, client) combination specified with ident:

```
    status=0

    rate=number
```

## RECIPIENT RATE CONTROL

```

```

To register a recipient request send the following request to the anvil(8) server:

```
    request=recipient

    ident=string
```

The anvil(8) server answers with the number of recipient addresses per unit time for the (service, client) combination specified with ident:

```
    status=0

    rate=number
```

## TLS SESSION NEGOTIATION RATE CONTROL

```

```

The features described in this section are available with Postfix 2.3 and later.

To register a request for a new (i.e. not cached) TLS session send the following request to the anvil(8) server:

```
    request=newtls

    ident=string
```

The anvil(8) server answers with the number of new TLS session requests per unit time for the (service, client) combination specified with ident:

```
    status=0

    rate=number
```

To retrieve new TLS session request rate information without updating the counter information, send:

```
    request=newtls_report

    ident=string
```

The anvil(8) server answers with the number of new TLS session requests per unit time for the (service, client) combination specified with ident:

```
    status=0

    rate=number
```

## AUTH RATE CONTROL

```

```

To register an AUTH request send the following request to the anvil(8) server:

```
    request=auth

    ident=string
```

The anvil(8) server answers with the number of auth requests per unit time for the (service, client) combination specified with ident:

```
    status=0

    rate=number
```

## SECURITY

```

```

The anvil(8) server does not talk to the network or to local users, and can run chrooted at fixed low privilege.

The anvil(8) server maintains an in-memory table with information about recent clients requests. No persistent state is kept because standard system library routines are not sufficiently robust for update-intensive applications.

Although the in-memory state is kept only temporarily, this may require a lot of memory on systems that handle connections from many remote clients. To reduce memory usage, reduce the time unit over which state is kept.

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

Upon exit, and every anvil_status_update_time seconds, the server logs the maximal count and rate values measured, together with (service, client) information and the time of day associated with those events. In order to avoid unnecessary overhead, no measurements are done for activity that isn't concurrency limited or rate limited.

## BUGS

Systems behind network address translating routers or proxies appear to have the same client address and can run into connection count and/or rate limits falsely.

In this preliminary implementation, a count (or rate) limited server process can have only one remote client at a time. If a server process reports multiple simultaneous clients, state is kept only for the last reported client.

The anvil(8) server automatically discards client request information after it expires. To prevent the anvil(8) server from discarding client request rate information too early or too late, a rate limited service should always register connect/disconnect events even when it does not explicitly limit them.

## CONFIGURATION PARAMETERS

```

```

On low-traffic mail systems, changes to main.cf are picked up automatically as anvil(8) processes run for only a limited amount of time. On other mail systems, use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

anvil_rate_time_unit (60s)

The time unit over which client connection rates and other rates are calculated.

anvil_status_update_time (600s)

How frequently the anvil(8) connection and rate limiting server logs peak usage information.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

## SEE ALSO

```
smtpd(8), Postfix SMTP server
postconf(5), configuration parameters
master(5), generic daemon options
```

## README FILES

```

```

Use "postconf readme_directory" or "postconf html_directory" to locate this information.

```
TUNING_README, performance tuning
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

The anvil service is available in Postfix 2.2 and later.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


bounce

title: bounce(8)

text:
# bounce(8)

## NAME
bounce - Postfix delivery status reports

## SYNOPSIS

```
bounce [generic Postfix daemon options]
```

## DESCRIPTION

The bounce(8) daemon maintains per-message log files with delivery status information. Each log file is named after the queue file that it corresponds to, and is kept in a queue subdirectory named after the service name in the master.cf file (either bounce, defer or trace). This program expects to be run from the master(8) process manager.

The bounce(8) daemon processes two types of service requests:

- Append a recipient (non-)delivery status record to a per-message log file.

- Enqueue a delivery status notification message, with a copy of a per-message log file and of the corresponding message. When the delivery status notification message is enqueued successfully, the per-message log file is deleted.

The software does a best notification effort. A non-delivery notification is sent even when the log file or the original message cannot be read.

Optionally, a bounce (defer, trace) client can request that the per-message log file be deleted when the requested operation fails. This is used by clients that cannot retry transactions by themselves, and that depend on retry logic in their own client.

## STANDARDS

```
RFC 822 (ARPA Internet Text Messages)
RFC 2045 (Format of Internet Message Bodies)
RFC 2822 (Internet Message Format)
RFC 3462 (Delivery Status Notifications)
RFC 3464 (Delivery Status Notifications)
RFC 3834 (Auto-Submitted: message header)
RFC 5322 (Internet Message Format)
RFC 6531 (Internationalized SMTP)
RFC 6532 (Internationalized Message Format)
RFC 6533 (Internationalized Delivery Status Notifications)
```

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically, as bounce(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

2bounce_notice_recipient (postmaster)

The recipient of undeliverable mail that cannot be returned to the sender.

backwards_bounce_logfile_compatibility (yes)

Produce additional bounce(8) logfile records that can be read by Postfix versions before 2.0.

bounce_notice_recipient (postmaster)

The recipient of postmaster notifications with the message headers of mail that Postfix did not deliver and of SMTP conversation transcripts of mail that Postfix did not receive.

bounce_size_limit (50000)

The maximal amount of original message text that is sent in a non-delivery notification.

bounce_template_file (empty)

Pathname of a configuration file with bounce message templates.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

delay_notice_recipient (postmaster)

The recipient of postmaster notifications with the message headers of mail that cannot be delivered within $delay_warning_time time units.

deliver_lock_attempts (20)

The maximal number of attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile.

deliver_lock_delay (1s)

The time between attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

internal_mail_filter_classes (empty)

What categories of Postfix-generated mail are subject to before-queue content inspection by non_smtpd_milters, header_checks and body_checks.

mail_name (Postfix)

The mail system name that is displayed in Received: headers, in the SMTP greeting banner, and in bounced mail.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

notify_classes (resource, software)

The list of error classes that are reported to the postmaster.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.0 and later:

smtputf8_autodetect_classes (sendmail, verify)

Detect that a message requires SMTPUTF8 support for the specified mail origin classes.

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.6 and later:

enable_threaded_bounces (no)

Enable non-delivery, success, and delay notifications that link to the original message by including a References: and In-Reply-To: header with the original Message-ID value.

Available in Postfix 3.7 and later:

header_from_format (standard)

The format of the Postfix-generated From: header.

## FILES

```
/var/spool/postfix/bounce/* non-delivery records
/var/spool/postfix/defer/* non-delivery records
/var/spool/postfix/trace/* delivery status records
```

## SEE ALSO

```
bounce(5), bounce message template format
qmgr(8), queue manager
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


cleanup

title: cleanup(8)

text:
# cleanup(8)

## NAME
cleanup - canonicalize and enqueue Postfix message

## SYNOPSIS

```
cleanup [generic Postfix daemon options]
```

## DESCRIPTION

The cleanup(8) daemon processes inbound mail, inserts it into the incoming mail queue, and informs the queue manager of its arrival.

The cleanup(8) daemon performs the following transformations:

- Insert missing message headers: (Resent-) From:, To:, Message-Id:, and Date:.

This is enabled with the local_header_rewrite_clients and always_add_missing_headers parameter settings.

- Transform envelope and header addresses to the standard user@fully-qualified-domain form that is expected by other Postfix programs. This task depends on the trivial-rewrite(8) daemon.

The header transformation is enabled with the local_header_rewrite_clients parameter setting.

- Eliminate duplicate envelope recipient addresses.

This is enabled with the duplicate_filter_limit parameter setting.

- Remove message headers: Bcc, Content-Length, Resent-Bcc, Return-Path.

This is enabled with the message_drop_headers parameter setting.

- Optionally, rewrite all envelope and header addresses according to the mappings specified in the canonical(5) lookup tables.

The header transformation is enabled with the local_header_rewrite_clients parameter setting.

- Optionally, masquerade envelope sender addresses and message header addresses (i.e. strip host or domain information below all domains listed in the masquerade_domains parameter, except for user names listed in masquerade_exceptions). By default, address masquerading does not affect envelope recipients.

The header transformation is enabled with the local_header_rewrite_clients parameter setting.

- Optionally, expand envelope recipients according to information found in the virtual_alias_maps lookup tables.

The cleanup(8) daemon performs sanity checks on the content of each message. When it finds a problem, by default it returns a diagnostic status to the cleanup service client, and leaves it up to the client to deal with the problem. Alternatively, the client can request the cleanup(8) daemon to bounce the message back to the sender in case of trouble.

## STANDARDS

```
RFC 822 (ARPA Internet Text Messages)
RFC 2045 (MIME: Format of Internet Message Bodies)
RFC 2046 (MIME: Media Types)
RFC 2822 (Internet Message Format)
RFC 3463 (Enhanced Status Codes)
RFC 3464 (Delivery status notifications)
RFC 5322 (Internet Message Format)
```

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

## BUGS

Table-driven rewriting rules make it hard to express if then else and other logical relationships.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically, as cleanup(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

## COMPATIBILITY CONTROLS

```

```

undisclosed_recipients_header (see 'postconf -d' output)

Message header that the Postfix cleanup(8) server inserts when a message contains no To: or Cc: message header.

Available in Postfix version 2.1 only:

enable_errors_to (no)

Report mail delivery errors to the address specified with the non-standard Errors-To: message header, instead of the envelope sender address (this feature is removed with Postfix version 2.2, is turned off by default with Postfix version 2.1, and is always turned on with older Postfix versions).

Available in Postfix version 2.6 and later:

always_add_missing_headers (no)

Always add (Resent-) From:, To:, Date: or Message-ID: headers when not present.

Available in Postfix version 2.9 and later:

enable_long_queue_ids (no)

Enable long, non-repeating, queue IDs (queue file names).

Available in Postfix version 3.0 and later:

message_drop_headers (bcc, content-length, resent-bcc, return-path)

Names of message headers that the cleanup(8) daemon will remove after applying header_checks(5) and before invoking Milter applications.

header_from_format (standard)

The format of the Postfix-generated From: header.

## BUILT-IN CONTENT FILTERING CONTROLS

```

```

Postfix built-in content filtering is meant to stop a flood of worms or viruses. It is not a general content filter.

body_checks (empty)

Optional lookup tables for content inspection as specified in the body_checks(5) manual page.

header_checks (empty)

Optional lookup tables for content inspection of primary non-MIME message headers, as specified in the header_checks(5) manual page.

Available in Postfix version 2.0 and later:

body_checks_size_limit (51200)

How much text in a message body segment (or attachment, if you prefer to use that term) is subjected to body_checks inspection.

mime_header_checks ($header_checks)

Optional lookup tables for content inspection of MIME related message headers, as described in the header_checks(5) manual page.

nested_header_checks ($header_checks)

Optional lookup tables for content inspection of non-MIME message headers in attached messages, as described in the header_checks(5) manual page.

Available in Postfix version 2.3 and later:

message_reject_characters (empty)

The set of characters that Postfix will reject in message content.

message_strip_characters (empty)

The set of characters that Postfix will remove from message content.

Available in Postfix version 3.9, 3.8.5, 3.7.10, 3.6.14, 3.5.24, and later:

cleanup_replace_stray_cr_lf (yes)

Replace each stray <CR> or <LF> character in message content with a space character, to prevent outbound SMTP smuggling, and to make the evaluation of Postfix-added DKIM or other signatures independent from how a remote mail server handles such characters.

## BEFORE QUEUE MILTER CONTROLS

```

```

As of version 2.3, Postfix supports the Sendmail version 8 Milter (mail filter) protocol. When mail is not received via the smtpd(8) server, the cleanup(8) server will simulate SMTP events to the extent that this is possible. For details see the MILTER_README document.

non_smtpd_milters (empty)

A list of Milter (mail filter) applications for new mail that does not arrive via the Postfix smtpd(8) server.

milter_protocol (6)

The mail filter protocol version and optional protocol extensions for communication with a Milter application; prior to Postfix 2.6 the default protocol is 2.

milter_default_action (tempfail)

The default action when a Milter (mail filter) response is unavailable (for example, bad Postfix configuration or Milter failure).

milter_macro_daemon_name ($myhostname)

The {daemon_name} macro value for Milter (mail filter) applications.

milter_macro_v ($mail_name $mail_version)

The {v} macro value for Milter (mail filter) applications.

milter_connect_timeout (30s)

The time limit for connecting to a Milter (mail filter) application, and for negotiating protocol options.

milter_command_timeout (30s)

The time limit for sending an SMTP command to a Milter (mail filter) application, and for receiving the response.

milter_content_timeout (300s)

The time limit for sending message content to a Milter (mail filter) application, and for receiving the response.

milter_connect_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after completion of an SMTP connection.

milter_helo_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after the SMTP HELO or EHLO command.

milter_mail_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after the SMTP MAIL FROM command.

milter_rcpt_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after the SMTP RCPT TO command.

milter_data_macros (see 'postconf -d' output)

The macros that are sent to version 4 or higher Milter (mail filter) applications after the SMTP DATA command.

milter_unknown_command_macros (see 'postconf -d' output)

The macros that are sent to version 3 or higher Milter (mail filter) applications after an unknown SMTP command.

milter_end_of_data_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after the message end-of-data.

Available in Postfix version 2.5 and later:

milter_end_of_header_macros (see 'postconf -d' output)

The macros that are sent to Milter (mail filter) applications after the end of the message header.

Available in Postfix version 2.7 and later:

milter_header_checks (empty)

Optional lookup tables for content inspection of message headers that are produced by Milter applications.

Available in Postfix version 3.1 and later:

milter_macro_defaults (empty)

Optional list of name=value pairs that specify default values for arbitrary macros that Postfix may send to Milter applications.

## MIME PROCESSING CONTROLS

```

```

Available in Postfix version 2.0 and later:

disable_mime_input_processing (no)

Turn off MIME processing while receiving mail.

mime_boundary_length_limit (2048)

The maximal length of MIME multipart boundary strings.

mime_nesting_limit (100)

The maximal recursion level that the MIME processor will handle.

strict_8bitmime (no)

Enable both strict_7bit_headers and strict_8bitmime_body.

strict_7bit_headers (no)

Reject mail with 8-bit text in message headers.

strict_8bitmime_body (no)

Reject 8-bit message body text without 8-bit MIME content encoding information.

strict_mime_encoding_domain (no)

Reject mail with invalid Content-Transfer-Encoding: information for the message/* or multipart/* MIME content types.

Available in Postfix version 2.5 and later:

detect_8bit_encoding_header (yes)

Automatically detect 8BITMIME body content by looking at Content-Transfer-Encoding: message headers; historically, this behavior was hard-coded to be "always on".

## AUTOMATIC BCC RECIPIENT CONTROLS

```

```

Postfix can automatically add BCC (blind carbon copy) when mail enters the mail system:

always_bcc (empty)

Optional address that receives a "blind carbon copy" of each message that is received by the Postfix mail system.

Available in Postfix version 2.1 and later:

sender_bcc_maps (empty)

Optional BCC (blind carbon-copy) address lookup tables, indexed by envelope sender address.

recipient_bcc_maps (empty)

Optional BCC (blind carbon-copy) address lookup tables, indexed by envelope recipient address.

## ADDRESS TRANSFORMATION CONTROLS

```

```

Address rewriting is delegated to the trivial-rewrite(8) daemon. The cleanup(8) server implements table driven address mapping.

empty_address_recipient (MAILER-DAEMON)

The recipient of mail addressed to the null address.

canonical_maps (empty)

Optional address mapping lookup tables for message headers and envelopes.

recipient_canonical_maps (empty)

Optional address mapping lookup tables for envelope and header recipient addresses.

sender_canonical_maps (empty)

Optional address mapping lookup tables for envelope and header sender addresses.

masquerade_classes (envelope_sender, header_sender, header_recipient)

What addresses are subject to address masquerading.

masquerade_domains (empty)

Optional list of domains whose subdomain structure will be stripped off in email addresses.

masquerade_exceptions (empty)

Optional list of user names that are not subjected to address masquerading, even when their addresses match $masquerade_domains.

propagate_unmatched_extensions (canonical, virtual)

What address lookup tables copy an address extension from the lookup key to the lookup result.

Available before Postfix version 2.0:

virtual_maps (empty)

Optional lookup tables with a) names of domains for which all addresses are aliased to addresses in other local or remote domains, and b) addresses that are aliased to addresses in other local or remote domains.

Available in Postfix version 2.0 and later:

virtual_alias_maps ($virtual_maps)

Optional lookup tables that alias specific mail addresses or domains to other local or remote addresses.

Available in Postfix version 2.2 and later:

canonical_classes (envelope_sender, envelope_recipient, header_sender, header_recipient)

What addresses are subject to canonical_maps address mapping.

recipient_canonical_classes (envelope_recipient, header_recipient)

What addresses are subject to recipient_canonical_maps address mapping.

sender_canonical_classes (envelope_sender, header_sender)

What addresses are subject to sender_canonical_maps address mapping.

remote_header_rewrite_domain (empty)

Rewrite or add message headers in mail from remote clients if the remote_header_rewrite_domain parameter value is non-empty, updating incomplete addresses with the domain specified in the remote_header_rewrite_domain parameter, and adding missing headers.

## RESOURCE AND RATE CONTROLS

```

```

duplicate_filter_limit (1000)

The maximal number of addresses remembered by the address duplicate filter for aliases(5) or virtual(5) alias expansion, or for showq(8) queue displays.

header_size_limit (102400)

The maximal amount of memory in bytes for storing a message header.

hopcount_limit (50)

The maximal number of Received: message headers that is allowed in the primary message headers.

in_flow_delay (1s)

Time to pause before accepting a new message, when the message arrival rate exceeds the message delivery rate.

message_size_limit (10240000)

The maximal size in bytes of a message, including envelope information.

Available in Postfix version 2.0 and later:

header_address_token_limit (10240)

The maximal number of address tokens are allowed in an address message header.

mime_boundary_length_limit (2048)

The maximal length of MIME multipart boundary strings.

mime_nesting_limit (100)

The maximal recursion level that the MIME processor will handle.

queue_file_attribute_count_limit (100)

The maximal number of (name=value) attributes that may be stored in a Postfix queue file.

Available in Postfix version 2.1 and later:

virtual_alias_expansion_limit (1000)

The maximal number of addresses that virtual alias expansion produces from each original recipient.

virtual_alias_recursion_limit (1000)

The maximal nesting depth of virtual alias expansion.

Available in Postfix version 3.0 and later:

virtual_alias_address_length_limit (1000)

The maximal length of an email address after virtual alias expansion.

## SMTPUTF8 CONTROLS

```

```

Preliminary SMTPUTF8 support is introduced with Postfix 3.0.

smtputf8_enable (yes)

Enable preliminary SMTPUTF8 support for the protocols described in RFC 6531, RFC 6532, and RFC 6533.

smtputf8_autodetect_classes (sendmail, verify)

Detect that a message requires SMTPUTF8 support for the specified mail origin classes.

Available in Postfix version 3.2 and later:

enable_idna2003_compatibility (no)

Enable 'transitional' compatibility between IDNA2003 and IDNA2008, when converting UTF-8 domain names to/from the ASCII form that is used for DNS lookups.

## MISCELLANEOUS CONTROLS

```

```

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

delay_logging_resolution_limit (2)

The maximal number of digits after the decimal point when logging sub-second delay values.

delay_warning_time (0h)

The time after which the sender receives a copy of the message headers of mail that is still queued.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

myhostname (see 'postconf -d' output)

The internet hostname of this mail system.

myorigin ($myhostname)

The domain name that locally-posted mail appears to come from, and that locally posted mail is delivered to.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

soft_bounce (no)

Safety net to keep mail queued that would otherwise be returned to the sender.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix version 2.1 and later:

enable_original_recipient (yes)

Enable support for the original recipient address after an address is rewritten to a different address (for example with aliasing or with canonical mapping).

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.5 and later:

info_log_address_format (external)

The email address form that will be used in non-debug logging (info, warning, etc.).

## FILES

```
/etc/postfix/canonical*, canonical mapping table
/etc/postfix/virtual*, virtual mapping table
```

## SEE ALSO

```
trivial-rewrite(8), address rewriting
qmgr(8), queue manager
header_checks(5), message header content inspection
body_checks(5), body parts content inspection
canonical(5), canonical address lookup table format
virtual(5), virtual alias lookup table format
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## README FILES

```

```

Use "postconf readme_directory" or "postconf html_directory" to locate this information.

```
ADDRESS_REWRITING_README Postfix address manipulation
CONTENT_INSPECTION_README content inspection
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


discard

title: discard(8)

text:
# discard(8)

## NAME
discard - Postfix discard mail delivery agent

## SYNOPSIS

```
discard [generic Postfix daemon options]
```

## DESCRIPTION

The Postfix discard(8) delivery agent processes delivery requests from the queue manager. Each request specifies a queue file, a sender address, a next-hop destination that is treated as the reason for discarding the mail, and recipient information. The reason may be prefixed with an RFC 3463-compatible detail code. This program expects to be run from the master(8) process manager.

The discard(8) delivery agent pretends to deliver all recipients in the delivery request, logs the "next-hop" destination as the reason for discarding the mail, updates the queue file, and either marks recipients as finished or informs the queue manager that delivery should be tried again at a later time.

Delivery status reports are sent to the trace(8) daemon as appropriate.

## SECURITY

```

```

The discard(8) mailer is not security-sensitive. It does not talk to the network, and can be run chrooted at fixed low privilege.

## STANDARDS

```
RFC 3463 (Enhanced Status Codes)
```

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

Depending on the setting of the notify_classes parameter, the postmaster is notified of bounces and of other trouble.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically as discard(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

delay_logging_resolution_limit (2)

The maximal number of digits after the decimal point when logging sub-second delay values.

double_bounce_sender (double-bounce)

The sender address of postmaster notifications that are generated by the mail system.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

## SEE ALSO

```
qmgr(8), queue manager
bounce(8), delivery status reports
error(8), Postfix error delivery agent
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

This service was introduced with Postfix version 2.2.

## AUTHOR(S)

```
Victor Duchovni
Morgan Stanley
Based on code by:
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


dnsblog

title: dnsblog(8)

text:
# dnsblog(8)

## NAME
dnsblog - Postfix DNS allow/denylist logger

## SYNOPSIS

```
dnsblog [generic Postfix daemon options]
```

## DESCRIPTION

The dnsblog(8) server implements an ad-hoc DNS allow/denylist lookup service. This may eventually be replaced by an UDP client that is built directly into the postscreen(8) server.

## PROTOCOL

```

```

With each connection, the dnsblog(8) server receives a DNS allow/denylist domain name, an IP address, and an ID. If the IP address is listed under the DNS allow/denylist, the dnsblog(8) server logs the match and replies with the query arguments plus an address list with the resulting IP addresses, separated by whitespace, and the reply TTL. Otherwise it replies with the query arguments plus an empty address list and the reply TTL; the reply TTL is -1 if there is no reply, or a negative reply that contains no SOA record. Finally, the dnsblog(8) server closes the connection.

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically, as dnsblog(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

postscreen_dnsbl_sites (empty)

Optional list of patterns with DNS allow/denylist domains, filters and weight factors.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

## SEE ALSO

```
smtpd(8), Postfix SMTP server
postconf(5), configuration parameters
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

This service was introduced with Postfix version 2.8.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


error

title: error(8)

text:
# error(8)

## NAME
error - Postfix error/retry mail delivery agent

## SYNOPSIS

```
error [generic Postfix daemon options]
```

## DESCRIPTION

The Postfix error(8) delivery agent processes delivery requests from the queue manager. Each request specifies a queue file, a sender address, the reason for non-delivery (specified as the next-hop destination), and recipient information. The reason may be prefixed with an RFC 3463-compatible detail code; if none is specified a default 4.0.0 or 5.0.0 code is used instead. This program expects to be run from the master(8) process manager.

Depending on the service name in master.cf, error or retry, the server bounces or defers all recipients in the delivery request using the "next-hop" information as the reason for non-delivery. The retry service name is supported as of Postfix 2.4.

Delivery status reports are sent to the bounce(8), defer(8) or trace(8) daemon as appropriate.

## SECURITY

```

```

The error(8) mailer is not security-sensitive. It does not talk to the network, and can be run chrooted at fixed low privilege.

## STANDARDS

```
RFC 3463 (Enhanced Status Codes)
```

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

Depending on the setting of the notify_classes parameter, the postmaster is notified of bounces and of other trouble.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically as error(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

2bounce_notice_recipient (postmaster)

The recipient of undeliverable mail that cannot be returned to the sender.

bounce_notice_recipient (postmaster)

The recipient of postmaster notifications with the message headers of mail that Postfix did not deliver and of SMTP conversation transcripts of mail that Postfix did not receive.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

delay_logging_resolution_limit (2)

The maximal number of digits after the decimal point when logging sub-second delay values.

double_bounce_sender (double-bounce)

The sender address of postmaster notifications that are generated by the mail system.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

notify_classes (resource, software)

The list of error classes that are reported to the postmaster.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

## SEE ALSO

```
qmgr(8), queue manager
bounce(8), delivery status reports
discard(8), Postfix discard delivery agent
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


flush

title: flush(8)

text:
# flush(8)

## NAME
flush - Postfix fast flush server

## SYNOPSIS

```
flush [generic Postfix daemon options]
```

## DESCRIPTION

The flush(8) server maintains a record of deferred mail by destination. This information is used to improve the performance of the SMTP ETRN request, and of its command-line equivalent, "sendmail -qR" or "postqueue -f". This program expects to be run from the master(8) process manager.

The record is implemented as a per-destination logfile with as contents the queue IDs of deferred mail. A logfile is append-only, and is truncated when delivery is requested for the corresponding destination. A destination is the part on the right-hand side of the right-most @ in an email address.

Per-destination logfiles of deferred mail are maintained only for eligible destinations. The list of eligible destinations is specified with the fast_flush_domains configuration parameter, which defaults to $relay_domains.

This server implements the following requests:

add sitename queueid

Inform the flush(8) server that the message with the specified queue ID is queued for the specified destination.

send_site sitename

Request delivery of mail that is queued for the specified destination.

send_file queueid

Request delivery of the specified deferred message.

refresh

Refresh non-empty per-destination logfiles that were not read in $fast_flush_refresh_time hours, by simulating send requests (see above) for the corresponding destinations. Delete empty per-destination logfiles that were not updated in $fast_flush_purge_time days.

This request completes in the background.

purge

Do a refresh for all per-destination logfiles.

## SECURITY

```

```

The flush(8) server is not security-sensitive. It does not talk to the network, and it does not talk to local users. The fast flush server can run chrooted at fixed low privilege.

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

## BUGS

Fast flush logfiles are truncated only after a "send" request, not when mail is actually delivered, and therefore can accumulate outdated or redundant data. In order to maintain sanity, "refresh" must be executed periodically. This can be automated with a suitable wakeup timer setting in the master.cf configuration file.

Upon receipt of a request to deliver mail for an eligible destination, the flush(8) server requests delivery of all messages that are listed in that destination's logfile, regardless of the recipients of those messages. This is not an issue for mail that is sent to a relay_domains destination because such mail typically only has recipients in one domain.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically as flush(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

fast_flush_domains ($relay_domains)

Optional list of destinations that are eligible for per-destination logfiles with mail that is queued to those destinations.

fast_flush_refresh_time (12h)

The time after which a non-empty but unread per-destination "fast flush" logfile needs to be refreshed.

fast_flush_purge_time (7d)

The time after which an empty per-destination "fast flush" logfile is deleted.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

parent_domain_matches_subdomains (see 'postconf -d' output)

A list of Postfix features where the pattern "example.com" also matches subdomains of example.com, instead of requiring an explicit ".example.com" pattern.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

## FILES

```
/var/spool/postfix/flush, "fast flush" logfiles.
```

## SEE ALSO

```
smtpd(8), SMTP server
qmgr(8), queue manager
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## README FILES

```

```

Use "postconf readme_directory" or "postconf html_directory" to locate this information.

```
ETRN_README, Postfix ETRN howto
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

This service was introduced with Postfix version 1.0.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


local

title: local(8)

text:
# local(8)

## NAME
local - Postfix local mail delivery

## SYNOPSIS

```
local [generic Postfix daemon options]
```

## DESCRIPTION

The local(8) daemon processes delivery requests from the Postfix queue manager to deliver mail to local recipients. Each delivery request specifies a queue file, a sender address, a domain or host to deliver to, and one or more recipients. This program expects to be run from the master(8) process manager.

The local(8) daemon updates queue files and marks recipients as finished, or it informs the queue manager that delivery should be tried again at a later time. Delivery status reports are sent to the bounce(8), defer(8) or trace(8) daemon as appropriate.

## CASE FOLDING

```

```

All delivery decisions are made using the bare recipient name (i.e. the address localpart), folded to lower case. See also under ADDRESS EXTENSION below for a few exceptions.

## SYSTEM-WIDE AND USER-LEVEL ALIASING

```

```

The system administrator can set up one or more system-wide sendmail-style alias databases. Users can have sendmail-style ~/.forward files. Mail for name is delivered to the alias name, to destinations in ~name/.forward, to the mailbox owned by the user name, or it is sent back as undeliverable.

The system administrator can specify a comma/space separated list of ~/.forward like files through the forward_path configuration parameter. Upon delivery, the local delivery agent tries each pathname in the list until a file is found.

Delivery via ~/.forward files is done with the privileges of the recipient. Thus, ~/.forward like files must be readable by the recipient, and their parent directory needs to have "execute" permission for the recipient.

The forward_path parameter is subject to interpolation of $user (recipient username), $home (recipient home directory), $shell (recipient shell), $recipient (complete recipient address), $extension (recipient address extension), $domain (recipient domain), $local (entire recipient address localpart) and $recipient_delimiter. The forms ${name?value} and ${name?{value}} (Postfix 3.0 and later) expand conditionally to value when $name is defined, and the forms ${name:value} ${name:{value}} (Postfix 3.0 and later) expand conditionally to value when $name is not defined. The form ${name?{value1}:{value2}} (Postfix 3.0 and later) expands conditionally to value1 when $name is defined, or value2 otherwise. Characters that may have special meaning to the shell or file system are replaced with underscores. The list of acceptable characters is specified with the forward_expansion_filter configuration parameter.

An alias or ~/.forward file may list any combination of external commands, destination file names, :include: directives, or mail addresses. See aliases(5) for a precise description. Each line in a user's .forward file has the same syntax as the right-hand part of an alias.

When an address is found in its own alias expansion, delivery is made to the user instead. When a user is listed in the user's own ~/.forward file, delivery is made to the user's mailbox instead. An empty ~/.forward file means do not forward mail.

In order to prevent the mail system from using up unreasonable amounts of memory, input records read from :include: or from ~/.forward files are broken up into chunks of length line_length_limit.

While expanding aliases, ~/.forward files, and so on, the program attempts to avoid duplicate deliveries. The duplicate_filter_limit configuration parameter limits the number of remembered recipients.

## MAIL FORWARDING

```

```

For the sake of reliability, forwarded mail is re-submitted as a new message, so that each recipient has a separate on-file delivery status record.

In order to stop mail forwarding loops early, the software adds an optional Delivered-To: header with the final envelope recipient address. If mail arrives for a recipient that is already listed in a Delivered-To: header, the message is bounced.

## MAILBOX DELIVERY

```

```

The default per-user mailbox is a file in the UNIX mail spool directory (/var/mail/user or /var/spool/mail/user); the location can be specified with the mail_spool_directory configuration parameter. Specify a name ending in / for qmail-compatible maildir delivery.

Alternatively, the per-user mailbox can be a file in the user's home directory with a name specified via the home_mailbox configuration parameter. Specify a relative path name. Specify a name ending in / for qmail-compatible maildir delivery.

Mailbox delivery can be delegated to an external command specified with the mailbox_command_maps and mailbox_command configuration parameters. The command executes with the privileges of the recipient user (exceptions: secondary groups are not enabled; in case of delivery as root, the command executes with the privileges of default_privs).

Mailbox delivery can be delegated to alternative message transports specified in the master.cf file. The mailbox_transport_maps and mailbox_transport configuration parameters specify an optional message transport that is to be used for all local recipients, regardless of whether they are found in the UNIX passwd database. The fallback_transport_maps and fallback_transport parameters specify an optional message transport for recipients that are not found in the aliases(5) or UNIX passwd database.

In the case of UNIX-style mailbox delivery, the local(8) daemon prepends a "From sender time_stamp" envelope header to each message, prepends an X-Original-To: header with the recipient address as given to Postfix, prepends an optional Delivered-To: header with the final envelope recipient address, prepends a Return-Path: header with the envelope sender address, prepends a > character to lines beginning with "From ", and appends an empty line. The mailbox is locked for exclusive access while delivery is in progress. In case of problems, an attempt is made to truncate the mailbox to its original length.

In the case of maildir delivery, the local daemon prepends an optional Delivered-To: header with the final envelope recipient address, prepends an X-Original-To: header with the recipient address as given to Postfix, and prepends a Return-Path: header with the envelope sender address.

## EXTERNAL COMMAND DELIVERY

```

```

The allow_mail_to_commands configuration parameter restricts delivery to external commands. The default setting (alias, forward) forbids command destinations in :include: files.

Optionally, the process working directory is changed to the path specified with command_execution_directory (Postfix 2.2 and later). Failure to change directory causes mail to be deferred.

The command_execution_directory parameter value is subject to interpolation of $user (recipient username), $home (recipient home directory), $shell (recipient shell), $recipient (complete recipient address), $extension (recipient address extension), $domain (recipient domain), $local (entire recipient address localpart) and $recipient_delimiter. The forms ${name?value} and ${name?{value}} (Postfix 3.0 and later) expand conditionally to value when $name is defined, and the forms ${name:value} and ${name:{value}} (Postfix 3.0 and later) expand conditionally to value when $name is not defined. The form ${name?{value1}:{value2}} (Postfix 3.0 and later) expands conditionally to value1 when $name is defined, or value2 otherwise. Characters that may have special meaning to the shell or file system are replaced with underscores. The list of acceptable characters is specified with the execution_directory_expansion_filter configuration parameter.

The command is executed directly where possible. Assistance by the shell (/bin/sh on UNIX systems) is used only when the command contains shell magic characters, or when the command invokes a shell built-in command.

A limited amount of command output (standard output and standard error) is captured for inclusion with non-delivery status reports. A command is forcibly terminated if it does not complete within command_time_limit seconds. Command exit status codes are expected to follow the conventions defined in <sysexits.h>. Exit status 0 means normal successful completion.

Postfix version 2.3 and later support RFC 3463-style enhanced status codes. If a command terminates with a non-zero exit status, and the command output begins with an enhanced status code, this status code takes precedence over the non-zero exit status.

A limited amount of message context is exported via environment variables. Characters that may have special meaning to the shell are replaced with underscores. The list of acceptable characters is specified with the command_expansion_filter configuration parameter.

SHELL

The recipient user's login shell.

HOME

The recipient user's home directory.

USER

The bare recipient name.

EXTENSION

The optional recipient address extension.

DOMAIN

The recipient address domain part.

LOGNAME

The bare recipient name.

LOCAL

The entire recipient address localpart (text to the left of the rightmost @ character).

ORIGINAL_RECIPIENT

The entire recipient address, before any address rewriting or aliasing (Postfix 2.5 and later).

RECIPIENT

The entire recipient address.

SENDER

The entire sender address.

Additional remote client information is made available via the following environment variables:

CLIENT_ADDRESS

Remote client network address. Available as of Postfix 2.2.

CLIENT_HELO

Remote client EHLO command parameter. Available as of Postfix 2.2.

CLIENT_HOSTNAME

Remote client hostname. Available as of Postfix 2.2.

CLIENT_PROTOCOL

Remote client protocol. Available as of Postfix 2.2.

SASL_METHOD

SASL authentication method specified in the remote client AUTH command. Available as of Postfix 2.2.

SASL_SENDER

SASL sender address specified in the remote client MAIL FROM command. Available as of Postfix 2.2.

SASL_USERNAME

SASL username specified in the remote client AUTH command. Available as of Postfix 2.2.

The PATH environment variable is always reset to a system-dependent default path, and environment variables whose names are blessed by the export_environment configuration parameter are exported unchanged.

The current working directory is the mail queue directory.

The local(8) daemon prepends a "From sender time_stamp" envelope header to each message, prepends an X-Original-To: header with the recipient address as given to Postfix, prepends an optional Delivered-To: header with the final recipient envelope address, prepends a Return-Path: header with the sender envelope address, and appends no empty line.

## EXTERNAL FILE DELIVERY

```

```

The delivery format depends on the destination filename syntax. The default is to use UNIX-style mailbox format. Specify a name ending in / for qmail-compatible maildir delivery.

The allow_mail_to_files configuration parameter restricts delivery to external files. The default setting (alias, forward) forbids file destinations in :include: files.

In the case of UNIX-style mailbox delivery, the local(8) daemon prepends a "From sender time_stamp" envelope header to each message, prepends an X-Original-To: header with the recipient address as given to Postfix, prepends an optional Delivered-To: header with the final recipient envelope address, prepends a > character to lines beginning with "From ", and appends an empty line. The envelope sender address is available in the Return-Path: header. When the destination is a regular file, it is locked for exclusive access while delivery is in progress. In case of problems, an attempt is made to truncate a regular file to its original length.

In the case of maildir delivery, the local daemon prepends an optional Delivered-To: header with the final envelope recipient address, and prepends an X-Original-To: header with the recipient address as given to Postfix. The envelope sender address is available in the Return-Path: header.

## ADDRESS EXTENSION

```

```

The optional recipient_delimiter configuration parameter specifies how to separate address extensions from local recipient names.

For example, with "recipient_delimiter = +", mail for name+foo is delivered to the alias name+foo or to the alias name, to the destinations listed in ~name/.forward+foo or in ~name/.forward, to the mailbox owned by the user name, or it is sent back as undeliverable.

## DELIVERY RIGHTS

```

```

Deliveries to external files and external commands are made with the rights of the receiving user on whose behalf the delivery is made. In the absence of a user context, the local(8) daemon uses the owner rights of the :include: file or alias database. When those files are owned by the superuser, delivery is made with the rights specified with the default_privs configuration parameter.

## STANDARDS

```
RFC 822 (ARPA Internet Text Messages)
RFC 3463 (Enhanced status codes)
```

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8). Corrupted message files are marked so that the queue manager can move them to the corrupt queue afterwards.

Depending on the setting of the notify_classes parameter, the postmaster is notified of bounces and of other trouble.

## SECURITY

```

```

The local(8) delivery agent needs a dual personality 1) to access the private Postfix queue and IPC mechanisms, 2) to impersonate the recipient and deliver to recipient-specified files or commands. It is therefore security sensitive.

The local(8) delivery agent disallows regular expression substitution of $1 etc. in alias_maps, because that would open a security hole.

The local(8) delivery agent will silently ignore requests to use the proxymap(8) server within alias_maps. Instead it will open the table directly. Before Postfix version 2.2, the local(8) delivery agent will terminate with a fatal error.

## BUGS

For security reasons, the message delivery status of external commands or of external files is never checkpointed to file. As a result, the program may occasionally deliver more than once to a command or external file. Better safe than sorry.

Mutually-recursive aliases or ~/.forward files are not detected early. The resulting mail forwarding loop is broken by the use of the Delivered-To: message header.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are picked up automatically, as local(8) processes run for only a limited amount of time. Use the command "postfix reload" to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

## COMPATIBILITY CONTROLS

```

```

biff (no)

Whether or not to use the local biff service.

expand_owner_alias (no)

When delivering to an alias "aliasname" that has an "owner-aliasname" companion alias, set the envelope sender address to the expansion of the "owner-aliasname" alias.

owner_request_special (yes)

Enable special treatment for owner-listname entries in the aliases(5) file, and don't split owner-listname and listname-request address localparts when the recipient_delimiter is set to "-".

sun_mailtool_compatibility (no)

Obsolete SUN mailtool compatibility feature.

Available in Postfix version 2.3 and later:

frozen_delivered_to (yes)

Update the local(8) delivery agent's idea of the Delivered-To: address (see prepend_delivered_header) only once, at the start of a delivery attempt; do not update the Delivered-To: address while expanding aliases or .forward files.

Available in Postfix version 2.5.3 and later:

strict_mailbox_ownership (yes)

Defer delivery when a mailbox file is not owned by its recipient.

reset_owner_alias (no)

Reset the local(8) delivery agent's idea of the owner-alias attribute, when delivering mail to a child alias that does not have its own owner alias.

Available in Postfix version 3.0 and later:

local_delivery_status_filter ($default_delivery_status_filter)

Optional filter for the local(8) delivery agent to change the status code or explanatory text of successful or unsuccessful deliveries.

## DELIVERY METHOD CONTROLS

```

```

The precedence of local(8) delivery methods from high to low is: aliases, .forward files, mailbox_transport_maps, mailbox_transport, mailbox_command_maps, mailbox_command, home_mailbox, mail_spool_directory, fallback_transport_maps, fallback_transport, and luser_relay.

alias_maps (see 'postconf -d' output)

The alias databases that are used for local(8) delivery.

forward_path (see 'postconf -d' output)

The local(8) delivery agent search list for finding a .forward file with user-specified delivery methods.

mailbox_transport_maps (empty)

Optional lookup tables with per-recipient message delivery transports to use for local(8) mailbox delivery, whether or not the recipients are found in the UNIX passwd database.

mailbox_transport (empty)

Optional message delivery transport that the local(8) delivery agent should use for mailbox delivery to all local recipients, whether or not they are found in the UNIX passwd database.

mailbox_command_maps (empty)

Optional lookup tables with per-recipient external commands to use for local(8) mailbox delivery.

mailbox_command (empty)

Optional external command that the local(8) delivery agent should use for mailbox delivery.

mailbox_unpriv_delivery (yes)

If enabled, then local(8) will not apply root privileges for mailbox delivery.

home_mailbox (empty)

Optional pathname of a mailbox file relative to a local(8) user's home directory.

mail_spool_directory (see 'postconf -d' output)

The directory where local(8) UNIX-style mailboxes are kept.

fallback_transport_maps (empty)

Optional lookup tables with per-recipient message delivery transports for recipients that the local(8) delivery agent could not find in the aliases(5) or UNIX password database.

fallback_transport (empty)

Optional message delivery transport that the local(8) delivery agent should use for names that are not found in the aliases(5) or UNIX password database.

luser_relay (empty)

Optional catch-all destination for unknown local(8) recipients.

Available in Postfix version 2.2 and later:

command_execution_directory (empty)

The local(8) delivery agent working directory for delivery to external commands.

## MAILBOX LOCKING CONTROLS

```

```

deliver_lock_attempts (20)

The maximal number of attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile.

deliver_lock_delay (1s)

The time between attempts to acquire an exclusive lock on a mailbox file or bounce(8) logfile.

stale_lock_time (500s)

The time after which a stale exclusive mailbox lockfile is removed.

mailbox_delivery_lock (see 'postconf -d' output)

How to lock a UNIX-style local(8) mailbox before attempting delivery.

## RESOURCE AND RATE CONTROLS

```

```

command_time_limit (1000s)

Time limit for delivery to external commands.

duplicate_filter_limit (1000)

The maximal number of addresses remembered by the address duplicate filter for aliases(5) or virtual(5) alias expansion, or for showq(8) queue displays.

mailbox_size_limit (51200000)

The maximal size of any local(8) individual mailbox or maildir file, or zero (no limit).

Implemented in the qmgr(8) daemon:

local_destination_concurrency_limit (2)

The maximal number of parallel deliveries via the local mail delivery transport to the same recipient (when "local_destination_recipient_limit = 1") or the maximal number of parallel deliveries to the same local domain (when "local_destination_recipient_limit > 1").

local_destination_recipient_limit (1)

The maximal number of recipients per message delivery via the local mail delivery transport.

## SECURITY CONTROLS

```

```

allow_mail_to_commands (alias, forward)

Restrict local(8) mail delivery to external commands.

allow_mail_to_files (alias, forward)

Restrict local(8) mail delivery to external files.

command_expansion_filter (see 'postconf -d' output)

Restrict the characters that the local(8) delivery agent allows in $name expansions of $mailbox_command and $command_execution_directory.

default_privs (postman)

The default rights used by the local(8) delivery agent for delivery to an external file or command.

forward_expansion_filter (see 'postconf -d' output)

Restrict the characters that the local(8) delivery agent allows in $name expansions of $forward_path.

Available in Postfix version 2.2 and later:

execution_directory_expansion_filter (see 'postconf -d' output)

Restrict the characters that the local(8) delivery agent allows in $name expansions of $command_execution_directory.

Available in Postfix version 2.5.3 and later:

strict_mailbox_ownership (yes)

Defer delivery when a mailbox file is not owned by its recipient.

## MISCELLANEOUS CONTROLS

```

```

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_timeout (18000s)

How much time a Postfix daemon process may take to handle a request before it is terminated by a built-in watchdog timer.

delay_logging_resolution_limit (2)

The maximal number of digits after the decimal point when logging sub-second delay values.

export_environment (see 'postconf -d' output)

The list of environment variables that a Postfix process will export to non-Postfix processes.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

local_command_shell (empty)

Optional shell program for local(8) delivery to non-Postfix commands.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

prepend_delivered_header (command, file, forward)

The message delivery contexts where the Postfix local(8) delivery agent prepends a Delivered-To: message header with the address that the mail was delivered to.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

propagate_unmatched_extensions (canonical, virtual)

What address lookup tables copy an address extension from the lookup key to the lookup result.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

recipient_delimiter (empty)

The set of characters that can separate an email address localpart, user name, or a .forward file name from its extension.

require_home_directory (no)

Require that a local(8) recipient's home directory exists before mail delivery is attempted.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix version 3.3 and later:

enable_original_recipient (yes)

Enable support for the original recipient address after an address is rewritten to a different address (for example with aliasing or with canonical mapping).

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.5 and later:

info_log_address_format (external)

The email address form that will be used in non-debug logging (info, warning, etc.).

## FILES

```
The following are examples; details differ between systems.
$HOME/.forward, per-user aliasing
/etc/aliases, system-wide alias database
/var/spool/mail, system mailboxes
```

## SEE ALSO

```
qmgr(8), queue manager
bounce(8), delivery status reports
newaliases(1), create/update alias database
postalias(1), create/update alias database
aliases(5), format of alias database
postconf(5), configuration parameters
master(5), generic daemon options
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## HISTORY

The Delivered-To: message header appears in the qmail system by Daniel Bernstein.

The maildir structure appears in the qmail system by Daniel Bernstein.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


master

title: master(8)

text:
# master(8)

## NAME
master - Postfix master process

## SYNOPSIS

```
master [-Dditvw] [-c config_dir] [-e exit_time]
```

## DESCRIPTION

The master(8) daemon is the resident process that runs Postfix daemons on demand: daemons to send or receive messages via the network, daemons to deliver mail locally, etc. These daemons are created on demand up to a configurable maximum number per service.

Postfix daemons terminate voluntarily, either after being idle for a configurable amount of time, or after having serviced a configurable number of requests. Exceptions to this rule are the resident queue manager, address verification server, and the TLS session cache and pseudo-random number server.

The behavior of the master(8) daemon is controlled by the master.cf configuration file, as described in master(5).

Options:

-c config_dir

Read the main.cf and master.cf configuration files in the named directory instead of the default configuration directory. This also overrides the configuration files for other Postfix daemon processes.

-D

After initialization, run a debugger on the master process. The debugging command is specified with the debugger_command in the main.cf global configuration file.

-d

Do not redirect stdin, stdout or stderr to /dev/null, and do not discard the controlling terminal. This must be used for debugging only.

-e exit_time

Terminate the master process after exit_time seconds. Child processes terminate at their convenience.

-i

Enable init mode: do not become a session or process group leader; and similar to -s, do not redirect stdout to /dev/null, so that "maillog_file = /dev/stdout" works. This mode is allowed only if the process ID equals 1. This feature is available in Postfix 3.3 and later.

-s

Do not redirect stdout to /dev/null, so that "maillog_file = /dev/stdout" works. This feature is available in Postfix 3.4 and later.

-t

Test mode. Return a zero exit status when the master.pid lock file does not exist or when that file is not locked. This is evidence that the master(8) daemon is not running.

-v

Enable verbose logging for debugging purposes. This option is passed on to child processes. Multiple -v options make the software increasingly verbose.

-w

Wait in a dummy foreground process, while the real master daemon initializes in a background process. The dummy foreground process returns a zero exit status only if the master daemon initialization is successful, and if it completes in a reasonable amount of time. This feature is available in Postfix 2.10 and later.

Signals:

SIGHUP

Upon receipt of a HUP signal (e.g., after "postfix reload"), the master process re-reads its configuration files. If a service has been removed from the master.cf file, its running processes are terminated immediately. Otherwise, running processes are allowed to terminate as soon as is convenient, so that changes in configuration settings affect only new service requests.

SIGTERM

Upon receipt of a TERM signal (e.g., after "postfix abort"), the master process passes the signal on to its child processes and terminates. This is useful for an emergency shutdown. Normally one would terminate only the master ("postfix stop") and allow running processes to finish what they are doing.

## DIAGNOSTICS

Problems are reported to syslogd(8) or postlogd(8). The exit status is non-zero in case of problems, including problems while initializing as a master daemon process in the background.

## ENVIRONMENT

```

```

MAIL_DEBUG

After initialization, start a debugger as specified with the debugger_command configuration parameter in the main.cf configuration file.

MAIL_CONFIG

Directory with Postfix configuration files.

## CONFIGURATION PARAMETERS

```

```

Unlike most Postfix daemon processes, the master(8) server does not automatically pick up changes to main.cf. Changes to master.cf are never picked up automatically. Use the "postfix reload" command after a configuration change.

## RESOURCE AND RATE CONTROLS

```

```

default_process_limit (100)

The default maximal number of Postfix child processes that provide a given service.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

service_throttle_time (60s)

How long the Postfix master(8) waits before forking a server that appears to be malfunctioning.

Available in Postfix version 2.6 and later:

master_service_disable (empty)

Selectively disable master(8) listener ports by service type or by service name and type.

## MISCELLANEOUS CONTROLS

```

```

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

daemon_directory (see 'postconf -d' output)

The directory with Postfix support programs and daemon programs.

debugger_command (empty)

The external command to execute when a Postfix daemon program is invoked with the -D option.

inet_interfaces (all)

The local network interface addresses that this mail system receives mail on.

inet_protocols (any)

The Internet protocols Postfix will attempt to use when making or accepting connections.

import_environment (see 'postconf -d' output)

The list of environment variables that a privileged Postfix process will import from a non-Postfix parent process, or name=value environment overrides.

mail_owner (postfix)

The UNIX system account that owns the Postfix queue and most Postfix daemon processes.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.6 and later:

known_tcp_ports (lmtp=24, smtp=25, smtps=submissions=465, submission=587)

Optional setting that avoids lookups in the services(5) database.

## FILES

```

```

To expand the directory names below into their actual values, use the command "postconf config_directory" etc.

```
$config_directory/main.cf, global configuration file.
$config_directory/master.cf, master server configuration file.
$queue_directory/pid/master.pid, master lock file.
$data_directory/master.lock, master lock file.
```

## SEE ALSO

```
qmgr(8), queue manager
verify(8), address verification
master(5), master.cf configuration file syntax
postconf(5), main.cf configuration file syntax
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


oqmgr

title: oqmgr(8)

text:
# oqmgr(8)

## NAME
oqmgr - old Postfix queue manager

## SYNOPSIS

```
oqmgr [generic Postfix daemon options]
```

## DESCRIPTION

The oqmgr(8) daemon awaits the arrival of incoming mail and arranges for its delivery via Postfix delivery processes. The actual mail routing strategy is delegated to the trivial-rewrite(8) daemon. This program expects to be run from the master(8) process manager.

Mail addressed to the local double-bounce address is logged and discarded. This stops potential loops caused by undeliverable bounce notifications.

## MAIL QUEUES

```

```

The oqmgr(8) daemon maintains the following queues:

incoming

Inbound mail from the network, or mail picked up by the local pickup(8) agent from the maildrop directory.

active

Messages that the queue manager has opened for delivery. Only a limited number of messages is allowed to enter the active queue (leaky bucket strategy, for a fixed delivery rate).

deferred

Mail that could not be delivered upon the first attempt. The queue manager implements exponential backoff by doubling the time between delivery attempts.

corrupt

Unreadable or damaged queue files are moved here for inspection.

hold

Messages that are kept "on hold" are kept here until someone sets them free.

## DELIVERY STATUS REPORTS

```

```

The oqmgr(8) daemon keeps an eye on per-message delivery status reports in the following directories. Each status report file has the same name as the corresponding message file:

bounce

Per-recipient status information about why mail is bounced. These files are maintained by the bounce(8) daemon.

defer

Per-recipient status information about why mail is delayed. These files are maintained by the defer(8) daemon.

trace

Per-recipient status information as requested with the Postfix "sendmail -v" or "sendmail -bv" command. These files are maintained by the trace(8) daemon.

The oqmgr(8) daemon is responsible for asking the bounce(8), defer(8) or trace(8) daemons to send delivery reports.

## STRATEGIES

```

```

The queue manager implements a variety of strategies for either opening queue files (input) or for message delivery (output).

leaky bucket

This strategy limits the number of messages in the active queue and prevents the queue manager from running out of memory under heavy load.

fairness

When the active queue has room, the queue manager takes one message from the incoming queue and one from the deferred queue. This prevents a large mail backlog from blocking the delivery of new mail.

slow start

This strategy eliminates "thundering herd" problems by slowly adjusting the number of parallel deliveries to the same destination.

round robin

The queue manager sorts delivery requests by destination. Round-robin selection prevents one destination from dominating deliveries to other destinations.

exponential backoff

Mail that cannot be delivered upon the first attempt is deferred. The time interval between delivery attempts is doubled after each attempt.

destination status cache

The queue manager avoids unnecessary delivery attempts by maintaining a short-term, in-memory list of unreachable destinations.

## TRIGGERS

```

```

On an idle system, the queue manager waits for the arrival of trigger events, or it waits for a timer to go off. A trigger is a one-byte message. Depending on the message received, the queue manager performs one of the following actions (the message is followed by the symbolic constant used internally by the software):

D (QMGR_REQ_SCAN_DEFERRED)

Start a deferred queue scan. If a deferred queue scan is already in progress, that scan will be restarted as soon as it finishes.

I (QMGR_REQ_SCAN_INCOMING)

Start an incoming queue scan. If an incoming queue scan is already in progress, that scan will be restarted as soon as it finishes.

A (QMGR_REQ_SCAN_ALL)

Ignore deferred queue file time stamps. The request affects the next deferred queue scan.

F (QMGR_REQ_FLUSH_DEAD)

Purge all information about dead transports and destinations.

W (TRIGGER_REQ_WAKEUP)

Wakeup call, This is used by the master server to instantiate servers that should not go away forever. The action is to start an incoming queue scan.

The oqmgr(8) daemon reads an entire buffer worth of triggers. Multiple identical trigger requests are collapsed into one, and trigger requests are sorted so that A and F precede D and I. Thus, in order to force a deferred queue run, one would request A F D; in order to notify the queue manager of the arrival of new mail one would request I.

## STANDARDS

```
RFC 3463 (Enhanced status codes)
RFC 3464 (Delivery status notifications)
```

## SECURITY

```

```

The oqmgr(8) daemon is not security sensitive. It reads single-character messages from untrusted local users, and thus may be susceptible to denial of service attacks. The oqmgr(8) daemon does not talk to the outside world, and it can be run at fixed low privilege in a chrooted environment.

## DIAGNOSTICS

Problems and transactions are logged to the syslogd(8) or postlogd(8) daemon. Corrupted message files are saved to the corrupt queue for further inspection.

Depending on the setting of the notify_classes parameter, the postmaster is notified of bounces and of other trouble.

## BUGS

A single queue manager process has to compete for disk access with multiple front-end processes such as cleanup(8). A sudden burst of inbound mail can negatively impact outbound delivery rates.

## CONFIGURATION PARAMETERS

```

```

Changes to main.cf are not picked up automatically, as oqmgr(8) is a persistent process. Use the command "postfix reload" after a configuration change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

In the text below, transport is the first field in a master.cf entry.

## COMPATIBILITY CONTROLS

```

```

Available before Postfix version 2.5:

allow_min_user (no)

Allow a sender or recipient address to have `-' as the first character.

Available with Postfix version 2.7 and later:

default_filter_nexthop (empty)

When a content_filter or FILTER request specifies no explicit next-hop destination, use $default_filter_nexthop instead; when that value is empty, use the domain in the recipient address.

## ACTIVE QUEUE CONTROLS

```

```

qmgr_clog_warn_time (300s)

The minimal delay between warnings that a specific destination is clogging up the Postfix active queue.

qmgr_message_active_limit (20000)

The maximal number of messages in the active queue.

qmgr_message_recipient_limit (20000)

The maximal number of recipients held in memory by the Postfix queue manager, and the maximal size of the short-term, in-memory "dead" destination status cache.

## DELIVERY CONCURRENCY CONTROLS

```

```

qmgr_fudge_factor (100)

Obsolete feature: the percentage of delivery resources that a busy mail system will use up for delivery of a large mailing list message.

initial_destination_concurrency (5)

The initial per-destination concurrency level for parallel delivery to the same destination.

default_destination_concurrency_limit (20)

The default maximal number of parallel deliveries to the same destination.

transport_destination_concurrency_limit ($default_destination_concurrency_limit)

A transport-specific override for the default_destination_concurrency_limit parameter value, where transport is the master.cf name of the message delivery transport.

Available in Postfix version 2.5 and later:

transport_initial_destination_concurrency ($initial_destination_concurrency)

A transport-specific override for the initial_destination_concurrency parameter value, where transport is the master.cf name of the message delivery transport.

default_destination_concurrency_failed_cohort_limit (1)

How many pseudo-cohorts must suffer connection or handshake failure before a specific destination is considered unavailable (and further delivery is suspended).

transport_destination_concurrency_failed_cohort_limit ($default_destination_concurrency_failed_cohort_limit)

A transport-specific override for the default_destination_concurrency_failed_cohort_limit parameter value, where transport is the master.cf name of the message delivery transport.

default_destination_concurrency_negative_feedback (1)

The per-destination amount of delivery concurrency negative feedback, after a delivery completes with a connection or handshake failure.

transport_destination_concurrency_negative_feedback ($default_destination_concurrency_negative_feedback)

A transport-specific override for the default_destination_concurrency_negative_feedback parameter value, where transport is the master.cf name of the message delivery transport.

default_destination_concurrency_positive_feedback (1)

The per-destination amount of delivery concurrency positive feedback, after a delivery completes without connection or handshake failure.

transport_destination_concurrency_positive_feedback ($default_destination_concurrency_positive_feedback)

A transport-specific override for the default_destination_concurrency_positive_feedback parameter value, where transport is the master.cf name of the message delivery transport.

destination_concurrency_feedback_debug (no)

Make the queue manager's feedback algorithm verbose for performance analysis purposes.

## RECIPIENT SCHEDULING CONTROLS

```

```

default_destination_recipient_limit (50)

The default maximal number of recipients per message delivery.

transport_destination_recipient_limit ($default_destination_recipient_limit)

A transport-specific override for the default_destination_recipient_limit parameter value, where transport is the master.cf name of the message delivery transport.

## OTHER RESOURCE AND RATE CONTROLS

```

```

minimal_backoff_time (300s)

The minimal time between attempts to deliver a deferred message; prior to Postfix 2.4 the default value was 1000s.

maximal_backoff_time (4000s)

The maximal time between attempts to deliver a deferred message.

maximal_queue_lifetime (5d)

Consider a message as undeliverable, when delivery fails with a temporary error, and the time in the queue has reached the maximal_queue_lifetime limit.

queue_run_delay (300s)

The time between deferred queue scans by the queue manager; prior to Postfix 2.4 the default value was 1000s.

transport_retry_time (60s)

The time between attempts by the Postfix queue manager to contact a malfunctioning message delivery transport.

Available in Postfix version 2.1 and later:

bounce_queue_lifetime (5d)

Consider a bounce message as undeliverable, when delivery fails with a temporary error, and the time in the queue has reached the bounce_queue_lifetime limit.

Available in Postfix version 2.5 and later:

default_destination_rate_delay (0s)

The default amount of delay that is inserted between individual message deliveries to the same destination and over the same message delivery transport.

transport_destination_rate_delay ($default_destination_rate_delay)

A transport-specific override for the default_destination_rate_delay parameter value, where transport is the master.cf name of the message delivery transport.

Available in Postfix version 3.1 and later:

default_transport_rate_delay (0s)

The default amount of delay that is inserted between individual message deliveries over the same message delivery transport, regardless of destination.

transport_transport_rate_delay ($default_transport_rate_delay)

A transport-specific override for the default_transport_rate_delay parameter value, where the initial transport in the parameter name is the master.cf name of the message delivery transport.

## SAFETY CONTROLS

```

```

qmgr_daemon_timeout (1000s)

How much time a Postfix queue manager process may take to handle a request before it is terminated by a built-in watchdog timer.

qmgr_ipc_timeout (60s)

The time limit for the queue manager to send or receive information over an internal communication channel.

Available in Postfix version 3.1 and later:

address_verify_pending_request_limit (see 'postconf -d' output)

A safety limit that prevents address verification requests from overwhelming the Postfix queue.

## MISCELLANEOUS CONTROLS

```

```

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

defer_transports (empty)

The names of message delivery transports that should not deliver mail unless someone issues "sendmail -q" or equivalent.

delay_logging_resolution_limit (2)

The maximal number of digits after the decimal point when logging sub-second delay values.

helpful_warnings (yes)

Log warnings about problematic configuration settings, and provide helpful suggestions.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix version 3.0 and later:

confirm_delay_cleared (no)

After sending a "your message is delayed" notification, inform the sender when the delay clears up.

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.5 and later:

info_log_address_format (external)

The email address form that will be used in non-debug logging (info, warning, etc.).

## FILES

```
/var/spool/postfix/incoming, incoming queue
/var/spool/postfix/active, active queue
/var/spool/postfix/deferred, deferred queue
/var/spool/postfix/bounce, non-delivery status
/var/spool/postfix/defer, non-delivery status
/var/spool/postfix/trace, delivery status
```

## SEE ALSO

```
trivial-rewrite(8), address routing
bounce(8), delivery status reports
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## README FILES

```

```

Use "postconf readme_directory" or "postconf html_directory" to locate this information.

```
QSHAPE_README, Postfix queue analysis
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```


pickup

title: pickup(8)

text:
# pickup(8)

## NAME
pickup - Postfix local mail pickup

## SYNOPSIS

```
pickup [generic Postfix daemon options]
```

## DESCRIPTION

The pickup(8) daemon waits for hints that new mail has been dropped into the maildrop directory, and feeds it into the cleanup(8) daemon. Ill-formatted files are deleted without notifying the originator. This program expects to be run from the master(8) process manager.

## STANDARDS

```

```

None. The pickup(8) daemon does not interact with the outside world.

## SECURITY

```

```

The pickup(8) daemon is moderately security sensitive. It runs with fixed low privilege and can run in a chrooted environment. However, the program reads files from potentially hostile users. The pickup(8) daemon opens no files for writing, is careful about what files it opens for reading, and does not actually touch any data that is sent to its public service endpoint.

## DIAGNOSTICS

Problems and transactions are logged to syslogd(8) or postlogd(8).

## BUGS

The pickup(8) daemon copies mail from file to the cleanup(8) daemon. It could avoid message copying overhead by sending a file descriptor instead of file data, but then the already complex cleanup(8) daemon would have to deal with unfiltered user data.

## CONFIGURATION PARAMETERS

```

```

As the pickup(8) daemon is a relatively long-running process, up to an hour may pass before a main.cf change takes effect. Use the command "postfix reload" command to speed up a change.

The text below provides only a parameter summary. See postconf(5) for more details including examples.

## CONTENT INSPECTION CONTROLS

```

```

content_filter (empty)

After the message is queued, send the entire message to the specified transport:destination.

receive_override_options (empty)

Enable or disable recipient validation, built-in content filtering, or address mapping.

## MISCELLANEOUS CONTROLS

```

```

config_directory (see 'postconf -d' output)

The default location of the Postfix main.cf and master.cf configuration files.

ipc_timeout (3600s)

The time limit for sending or receiving information over an internal communication channel.

line_length_limit (2048)

Upon input, long lines are chopped up into pieces of at most this length; upon delivery, long lines are reconstructed.

max_idle (100s)

The maximum amount of time that an idle Postfix daemon process waits for an incoming connection before terminating voluntarily.

max_use (100)

The maximal number of incoming connections that a Postfix daemon process will service before terminating voluntarily.

process_id (read-only)

The process ID of a Postfix command or daemon process.

process_name (read-only)

The process name of a Postfix command or daemon process.

queue_directory (see 'postconf -d' output)

The location of the Postfix top-level queue directory.

syslog_facility (mail)

The syslog facility of Postfix logging.

syslog_name (see 'postconf -d' output)

A prefix that is prepended to the process name in syslog records, so that, for example, "smtpd" becomes "prefix/smtpd".

Available in Postfix 3.3 and later:

service_name (read-only)

The master.cf service name of a Postfix daemon process.

Available in Postfix 3.5 and later:

info_log_address_format (external)

The email address form that will be used in non-debug logging (info, warning, etc.).

## SEE ALSO

```
cleanup(8), message canonicalization
sendmail(1), Sendmail-compatible interface
postdrop(1), mail posting agent
postconf(5), configuration parameters
master(5), generic daemon options
master(8), process manager
postlogd(8), Postfix logging
syslogd(8), system logging
```

## LICENSE

```

```

The Secure Mailer license must be distributed with this software.

## AUTHOR(S)

```
Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA
Wietse Venema
Google, Inc.
111 8th Avenue
New York, NY 10011, USA
```