    LOCAL(8)                                                              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 fin-
           ished, 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  send-
           mail-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 recip-
           ient.  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 (recip-
           ient  username),  $home  (recipient  home directory), $shell (recipient
           shell), $recipient (complete recipient address), $extension  (recipient
           address  extension), $domain (recipient domain), $local (entire recipi-
           ent   address   localpart)   and   $recipient_delimiter.   The    forms
           ${name?value} and ${name?{value}} (Postfix 3.0 and later) expand condi-
           tionally 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 accept-
           able characters is specified with the forward_expansion_filter configu-
           ration parameter.

           An  alias  or ~/.forward file may list any combination of external com-
           mands, destination file names, :include: directives, or mail addresses.
           See  aliases(5)  for a precise description. Each line in a user's .for-
           ward 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 ~/.for-
           ward 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 con-
           figuration 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  (excep-
           tions:  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 mail-
           box_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  fall-
           back_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 exclu-
           sive 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 com-
           mand destinations in :include: files.

           Optionally, the process working directory is changed to the path speci-
           fied 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 interpo-
           lation 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 condi-
           tionally   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  com-
           mand_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 vari-
           ables. Characters that may  have  special  meaning  to  the  shell  are
           replaced with underscores.  The list of acceptable characters is speci-
           fied with the command_expansion_filter configuration parameter.

           SHELL  The envelope recipient user's login shell.

           HOME   The envelope recipient user's home directory.

           USER   The bare envelope recipient name.

           EXTENSION
                  The optional envelope recipient address extension.

           DOMAIN The envelope recipient address domain part.

           LOGNAME
                  The bare envelope recipient name.

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

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

           RECIPIENT
                  The entire envelope recipient address.

           SENDER The entire envelope sender address.

           ENVID  The optional RFC 3461 envelope ID. Available as of Postfix  3.9.

           Additional  remote client information is made available via the follow-
           ing 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 des-
           tinations 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 destina-
           tions 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  postmas-
           ter 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 recipi-
           ent  and deliver to recipient-specified files or commands. It is there-
           fore 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  exter-
           nal 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  Deliv-
           ered-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 (yes)
                  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  list-
                  name-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  recipi-
                  ent.

           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_direc-
           tory, fallback_transport_maps, fallback_transport, and luser_relay.

           alias_maps (see 'postconf -d' output)
                  Optional lookup tables with aliases that apply only to  local(8)
                  recipients;  this is unlike virtual_alias_maps that apply to all
                  recipients: local(8), virtual, and remote.

           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.

           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 dupli-
                  cate 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_destina-
                  tion_recipient_limit  =  1")  or  the maximal number of parallel
                  deliveries  to  the  same  local  domain  (when  "local_destina-
                  tion_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_execu-
                  tion_directory.

           default_privs (nobody)
                  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 recipi-
                  ent.

    MISCELLANEOUS CONTROLS
           config_directory (see 'postconf -d' output)
                  The default location of the Postfix main.cf and  master.cf  con-
                  figuration 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  log-
                  ging 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 com-
                  mands.

           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) deliv-
                  ery 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  local-
                  part, 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

                                                                          LOCAL(8)