cleanup - canonicalize and enqueue Postfix message
cleanup [generic Postfix daemon options]
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.
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)
Problems and transactions are logged to syslogd(8) or
postlogd(8).
Table-driven rewriting rules make it hard to express if
then else and other logical relationships.
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.
- 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 (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:
- Names of message headers that the cleanup(8) daemon will remove
after applying header_checks(5) and before invoking Milter
applications.
- The format of the Postfix-generated From: header.
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.
- 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.
- Optional lookup tables for content inspection of MIME related message
headers, as described in the header_checks(5) manual page.
- 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.
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.
- 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:
- Automatically detect 8BITMIME body content by looking at
Content-Transfer-Encoding: message headers; historically, this behavior
was hard-coded to be "always on".
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 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 with aliases that apply to all recipients:
local(8), virtual, and remote; this is unlike alias_maps that apply
only to local(8) recipients.
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.
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.
- 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.).
Available in Postfix 3.9 and later:
- force_mime_input_conversion
(no)
- Convert body content that claims to be 8-bit into quoted-printable, before
header_checks, body_checks, Milters, and before after-queue content
filters.
/etc/postfix/canonical*, canonical mapping table
/etc/postfix/virtual*, virtual mapping table
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
Use "postconf readme_directory" or
"postconf html_directory" to locate this information.
ADDRESS_REWRITING_README Postfix address manipulation
CONTENT_INSPECTION_README content inspection
The Secure Mailer license must be distributed with this
software.
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