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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 mas-
       ter(8) process manager.

       The local(8) daemon updates queue files and marks  recipi-
       ents  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  excep-
       tions.

SYSTEM-WIDE AND USER-LEVEL ALIASING
       The  system  administrator  can set up one or more system-
       wide sendmail-style alias databases.  Users can have send-
       mail-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  sepa-
       rated  list  of  ~/.forward  like  files  through the for-
       ward_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  direc-
       tory),  $shell  (recipient  shell),  $recipient  (complete
       recipient address), $extension (recipient  address  exten-
       sion),  $domain (recipient domain), $local (entire recipi-
       ent address localpart) and $recipient_delimiter. The forms
       ${name?value}  and  ${name:value}  expand conditionally to
       value when $name is (is not) defined.  Characters that may
       have  special  meaning  to  the  shell  or file system are
       replaced by underscores.  The list of  acceptable  charac-
       ters  is  specified with the forward_expansion_filter con-
       figuration 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  pre-
       cise  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  unrea-
       sonable   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 dupli-
       cate_filter_limit  configuration parameter limits the num-
       ber of remembered recipients.

MAIL FORWARDING
       For the sake of reliability, forwarded mail is  re-submit-
       ted  as  a new message, so that each recipient has a sepa-
       rate on-file delivery status record.

       In order to stop mail forwarding loops early, the software
       adds an optional Delivered-To: header with the final enve-
       lope recipient address. If mail arrives  for  a  recipient
       that is already listed in a Delivered-To: header, the mes-
       sage 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_direc-
       tory  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_com-
       mand configuration parameters. The command  executes  with
       the  privileges  of  the  recipient user (exceptions: sec-
       ondary 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 mail-
       box_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 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 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 set-
       ting (alias,  forward)  forbids  command  destinations  in
       :include: files.

       Optionally,  the  process  working directory is changed to
       the path specified with command_execution_directory (Post-
       fix  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 $recipi-
       ent_delimiter.  The forms ${name?value} and  ${name:value}
       expand  conditionally  to  value  when  $name  is (is not)
       defined.  Characters that may have special meaning to  the
       shell  or  file  system  are replaced by underscores.  The
       list of acceptable characters is specified with the execu-
       tion_directory_expansion_filter configuration parameter.

       The  command  is  executed directly where possible. Assis-
       tance 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-deliv-
       ery 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  con-
       ventions  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  envi-
       ronment  variables. Characters that may have special mean-
       ing to the shell are replaced by underscores.  The list of
       acceptable characters is specified with the command_expan-
       sion_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).

       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 begin-
       ning with "From ", and appends an empty line.   The  enve-
       lope  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 reg-
       ular 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 enve-
       lope  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/.for-
       ward+foo or in ~name/.forward, to the mailbox owned by the
       user name, or it is sent back as undeliverable.

       In all cases the  local(8)  daemon  prepends  an  optional
       `Delivered-To:   header  line  with  the  final  recipient
       address.

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).   Cor-
       rupted  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 trou-
       ble.

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-speci-
       fied  files  or  commands. It is therefore security sensi-
       tive.

       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 check-
       pointed to file. As a result, the program may occasionally
       deliver more than once to a command or external file. Bet-
       ter 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 (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)
              Give special treatment to owner-listname and  list-
              name-request  address  localparts: don't split such
              addresses 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_deliv-
              ered_header)  only once, at the start of a delivery
              attempt; do not update  the  Delivered-To:  address
              while expanding aliases or .forward files.

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_trans-
       port_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 meth-
              ods.

       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) deliv-
              ery 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 command.

MAILBOX LOCKING CONTROLS
       deliver_lock_attempts (20)
              The maximal number of attempts to acquire an exclu-
              sive 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 vir-
              tual(5) alias expansion, or for showq(8) queue dis-
              plays.

       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_recipi-
              ent_limit > 1").

       local_destination_recipient_limit (1)
              The maximal number of recipients per message deliv-
              ery via the local mail delivery transport.

       mailbox_size_limit (51200000)
              The maximal size of any local(8) individual mailbox
              or maildir file, or zero (no limit).

SECURITY CONTROLS
       allow_mail_to_commands (alias, forward)
              Restrict local(8) mail delivery  to  external  com-
              mands.

       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_com-
              mand.

       default_privs (nobody)
              The default rights used by  the  local(8)  delivery
              agent for delivery to 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_execu-
              tion_directory.

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 command.

       max_idle (100s)
              The maximum amount of time  that  an  idle  Postfix
              daemon  process  waits for the next service request
              before exiting.

       max_use (100)
              The maximal number of connection requests before  a
              Postfix daemon process terminates.

       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  exten-
              sion from the lookup key to the lookup result.

       queue_directory (see 'postconf -d' output)
              The  location of the Postfix top-level queue direc-
              tory.

       recipient_delimiter (empty)
              The separator between user names and address exten-
              sions (user+foo).

       require_home_directory (no)
              Whether  or  not a local(8) recipient's home direc-
              tory must exist before mail delivery is  attempted.

       syslog_facility (mail)
              The syslog facility of Postfix logging.

       syslog_name (postfix)
              The  mail  system  name  that  is  prepended to the
              process name in syslog  records,  so  that  "smtpd"
              becomes, for example, "postfix/smtpd".

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
       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 sys-
       tem 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

                                                                      LOCAL(8)