cleanup – canonicalize and enqueue Postfix message

USAGE
       cleanup [generic Postfix daemon options]

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

       The cleanup daemon always performs the following transformations:

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

       ·      Extract envelope recipient addresses from (Resent-) To:, Cc: and
              Bcc: message headers when no recipients  are  specified  in  the
              message envelope.

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

       ·      Eliminate duplicate envelope recipient addresses.

       The following address transformations are optional:

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

       ·      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.

       ·      Optionally,  expand envelope recipients according to information
              found in the virtual(5) lookup tables.

       The cleanup daemon performs sanity checks on the content of  each  mes-
       sage.  When it finds a problem, by default it returns a diagnostic sta-
       tus to the client, and leaves it up to the  client  to  deal  with  the
       problem.  Alternatively,  the  client can request the cleanup 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)

DIAGNOSTICS
       Problems and transactions are logged to syslogd(8).

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

CONFIGURATION PARAMETERS
       The  following  main.cf parameters are especially relevant to this pro-
       gram. See the Postfix main.cf file for syntax details and  for  default
       values. Use the postfix reload command after a configuration change.

Content filtering
       body_checks
              Lookup  tables  with  content  filters  for  message body lines.
              These filters see physical lines one at a time, in chunks of  at
              most line_length_limit bytes.

       body_checks_size_limit
              The amount of content per message body segment that is subjected
              to $body_checks filtering.

       header_checks

       mime_header_checks (default: $header_checks)

       nested_header_checks (default: $header_checks)
              Lookup tables with content filters  for  message  header  lines:
              respectively,  these  are applied to the primary message headers
              (not including MIME headers), to the MIME  headers  anywhere  in
              the  message,  and  to the initial headers of attached messages.
              These filters see logical headers one at a time, including head-
              ers that span multiple lines.

MIME Processing
       disable_mime_input_processing
              While receiving, give no special treatment to Content-Type: mes-
              sage headers; all text after the initial message headers is con-
              sidered to be part of the message body.

       mime_boundary_length_limit
              The  amount  of  space that will be allocated for MIME multipart
              boundary strings. The MIME processor is  unable  to  distinguish
              between  boundary  strings  that  do  not  differ  in  the first
              $mime_boundary_length_limit characters.

       mime_nesting_limit
              The maximal nesting level of multipart mail that the  MIME  pro-
              cessor can handle. Refuse mail that is nested deeper.

       strict_8bitmime
              Turn on both strict_7bit_headers and strict_8bitmime_body.

       strict_7bit_headers
              Reject mail with 8-bit text in message headers. This blocks mail
              from poorly written applications.

       strict_8bitmime_body
              Reject mail with 8-bit text in content that claims to be  7-bit,
              or in content that has no explicit content encoding information.
              This blocks mail from poorly  written  mail  software.  Unfortu-
              nately,  this  also  breaks majordomo approval requests when the
              included request contains valid 8-bit MIME mail, and  it  breaks
              bounces from mailers that do not properly encapsulate 8-bit con-
              tent (for example, bounces from qmail or from  old  versions  of
              Postfix).

       strict_mime_encoding_domain
              Reject  mail with invalid Content-Transfer-Encoding: information
              for message/* or multipart/*. This blocks mail from poorly writ-
              ten software.

Miscellaneous
       always_bcc
              Address to send a copy of each message that enters the system.

       hopcount_limit
              Limit the number of Received: message headers.

       undisclosed_recipients_header
              The  header line that is inserted when no recipients were speci-
              fied in (Resent-)To: or (Resent-)Cc: message headers.

Address transformations
       empty_address_recipient
              The destination for undeliverable mail from <>.  This  substitu-
              tion is done before all other address rewriting.

       canonical_maps
              Address  mapping lookup table for sender and recipient addresses
              in envelopes and headers.

       recipient_canonical_maps
              Address mapping lookup table for envelope and  header  recipient
              addresses.

       sender_canonical_maps
              Address  mapping  lookup  table  for  envelope and header sender
              addresses.

       masquerade_classes
              List of address classes subject to masquerading: zero or more of
              envelope_sender,        envelope_recipient,       header_sender,
              header_recipient.

       masquerade_domains
              List of domains that hide their subdomain structure.

       masquerade_exceptions
              List of user names that are not subject to address masquerading.

       virtual_alias_maps
              Address mapping lookup table for envelope recipient addresses.

Resource controls
       duplicate_filter_limit
              Limits the number of envelope recipients that are remembered.

       header_address_token_limit
              Limits  the  number  of address tokens used to process a message
              header.

       header_size_limit
              Limits the amount of memory in bytes used  to  store  a  message
              header.

       in_flow_delay
              Amount  of  time  to  pause before accepting a message, when the
              message arrival rate exceeds the message delivery rate.

       extract_recipient_limit
              Limit the amount of recipients extracted from message headers.

SEE ALSO
       canonical(5) canonical address lookup table format
       qmgr(8) queue manager daemon
       syslogd(8) system logging
       virtual(5) virtual alias lookup table format

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

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