SMTPD(8)                                                              SMTPD(8)

NAME
       smtpd  - Postfix SMTP server SYNOPSIS smtpd [generic Post-
       fix daemon options]

DESCRIPTION
       The SMTP server accepts network  connection  requests  and
       performs  zero  or  more SMTP transactions per connection.
       Each received message is piped through the cleanup(8) dae-
       mon,  and  is placed into the incoming queue as one single
       queue file.  For  this  mode  of  operation,  the  program
       expects to be run from the master(8) process manager.

       Alternatively,  the  SMTP server takes an established con-
       nection on standard input and deposits  messages  directly
       into  the  maildrop  queue.  In this so-called stand-alone
       mode, the SMTP server can accept mail even while the  mail
       system is not running.

       The  SMTP server implements a variety of policies for con-
       nection requests, and for parameters given to HELO,  ETRN,
       MAIL  FROM,  VRFY  and RCPT TO commands. They are detailed
       below and in the main.cf configuration file.  SECURITY
       The SMTP server is moderately security-sensitive. It talks
       to  SMTP  clients  and  to DNS servers on the network. The
       SMTP server can be run chrooted at  fixed  low  privilege.
       STANDARDS  RFC 821 (SMTP protocol) RFC 1123 (Host require-
       ments) RFC 1652 (8bit-MIME transport) RFC 1869 (SMTP  ser-
       vice  extensions)  RFC 1870 (Message Size Declaration) RFC
       1985 (ETRN command) RFC 2554 (AUTH command) RFC 2821 (SMTP
       protocol)  RFC  2920  (SMTP Pipelining) RFC 3207 (STARTTLS
       command)

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

       Depending on the setting of the notify_classes  parameter,
       the  postmaster is notified of bounces, protocol problems,
       policy violations, and of  other  trouble.   CONFIGURATION
       PARAMETERS
       Changes   to  main.cf  are  picked  up  automatically,  as
       smtpd(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.  COMPATI-
       BILITY CONTROLS
       The following parameters work around implementation errors
       in other software, and/or allow you to override  standards
       in order to prevent undesirable use.

       broken_sasl_auth_clients (no)
              Enable  inter-operability  with  SMTP  clients that
              implement an obsolete version of the  AUTH  command
              (RFC 2554).

       disable_vrfy_command (no)
              Disable the SMTP VRFY command.

       smtpd_noop_commands (empty)
              List  of  commands  that  the  Postfix  SMTP server
              replies to with "250 Ok", without doing any  syntax
              checks and without changing state.

       strict_rfc821_envelopes (no)
              Require  that  addresses received in SMTP MAIL FROM
              and RCPT TO commands are enclosed with <>, and that
              those  addresses  do not contain RFC 822 style com-
              ments or phrases.

       Available in Postfix version 2.1 and later:

       resolve_null_domain (no)
              Resolve an address that ends in the "@" null domain
              as if the local hostname were specified, instead of
              rejecting the address as invalid.

       smtpd_reject_unlisted_sender (no)
              Request that the Postfix SMTP server  rejects  mail
              from   unknown   sender  addresses,  even  when  no
              explicit reject_unlisted_sender access  restriction
              is specified.

       smtpd_sasl_exceptions_networks (empty)
              What  SMTP clients Postfix will not offer AUTH sup-
              port to.

       Available in Postfix version 2.2 and later:

       smtpd_discard_ehlo_keyword_address_maps (empty)
              Lookup tables, indexed by the  remote  SMTP  client
              address,  with  case insensitive lists of EHLO key-
              words (pipelining, starttls, auth, etc.)  that  the
              SMTP server will not send in the EHLO response to a
              remote SMTP client.

       smtpd_discard_ehlo_keywords (empty)
              A case insensitive list of EHLO keywords  (pipelin-
              ing,  starttls,  auth,  etc.)  that the SMTP server
              will not send in the EHLO response to a remote SMTP
              client.  ADDRESS REWRITING CONTROLS
              See  the  ADDRESS_REWRITING_README  document  for a
              detailed discussion of Postfix address rewriting.

       receive_override_options (empty)
              Enable or disable  recipient  validation,  built-in
              content filtering, or address mapping.

       Available in Postfix version 2.2 and later:

       local_header_rewrite_clients (permit_inet_interfaces)
              Rewrite message header addresses in mail from these
              clients and update incomplete  addresses  with  the
              domain name in $myorigin or $mydomain; either don't
              rewrite message headers from other clients at  all,
              or  rewrite  message  headers and update incomplete
              addresses  with  the  domain   specified   in   the
              remote_header_rewrite_domain    parameter.    AFTER
              QUEUE EXTERNAL CONTENT INSPECTION CONTROLS
              As of version 1.0, Postfix  can  be  configured  to
              send  new  mail to an external content filter AFTER
              the mail is queued. This content filter is expected
              to  inject  mail back into a (Postfix or other) MTA
              for further delivery. See the  FILTER_README  docu-
              ment for details.

       content_filter (empty)
              The  name of a mail delivery transport that filters
              mail after it is  queued.   BEFORE  QUEUE  EXTERNAL
              CONTENT INSPECTION CONTROLS
              As  of  version 2.1, the Postfix SMTP server can be
              configured to send incoming  mail  to  a  real-time
              SMTP-based  content  filter  BEFORE mail is queued.
              This content filter is expected to inject mail back
              into  Postfix.  See the SMTPD_PROXY_README document
              for details on how to configure  and  operate  this
              feature.

       smtpd_proxy_filter (empty)
              The  hostname  and  TCP  port of the mail filtering
              proxy server.

       smtpd_proxy_ehlo ($myhostname)
              How the Postfix SMTP server announces itself to the
              proxy filter.

       smtpd_proxy_timeout (100s)
              The time limit for connecting to a proxy filter and
              for sending or receiving information.  GENERAL CON-
              TENT INSPECTION CONTROLS
              The  following  parameters  are applicable for both
              built-in and external content filters.

       Available in Postfix version 2.1 and later:

       receive_override_options (empty)
              Enable or disable  recipient  validation,  built-in
              content  filtering,  or  address mapping.  EXTERNAL
              CONTENT INSPECTION CONTROLS
              The following parameters are  applicable  for  both
              before-queue and after-queue content filtering.

       Available in Postfix version 2.1 and later:

       smtpd_authorized_xforward_hosts (empty)
              What  SMTP  clients are allowed to use the XFORWARD
              feature.  SASL AUTHENTICATION CONTROLS
              Postfix SASL support (RFC  2554)  can  be  used  to
              authenticate  remote  SMTP  clients  to the Postfix
              SMTP server, and to authenticate the  Postfix  SMTP
              client   to   a   remote   SMTP  server.   See  the
              SASL_README document for details.

       broken_sasl_auth_clients (no)
              Enable inter-operability  with  SMTP  clients  that
              implement  an  obsolete version of the AUTH command
              (RFC 2554).

       smtpd_sasl_auth_enable (no)
              Enable SASL  authentication  in  the  Postfix  SMTP
              server.

       smtpd_sasl_application_name (smtpd)
              The  application name used for SASL server initial-
              ization.

       smtpd_sasl_local_domain (empty)
              The name of the local SASL authentication realm.

       smtpd_sasl_security_options (noanonymous)
              Restrict what authentication mechanisms the Postfix
              SMTP server will offer to the client.

              Append  SASL  authenticated  username  in  Received
              header line.

       smtpd_sender_login_maps (empty)
              Optional lookup table with  the  SASL  login  names
              that own sender (MAIL FROM) addresses.

       smtpd_sasl_path
              The  path where SASL will look for plugins. This is
              a colon separated list  of  directories  where  the
              SASL plugins shared objects are located.  The first
              component of the path will also be the location  of
              the  SASL  configuration file. The default value is
              the null string, which will use the path defined in
              the SASL library.

       Available in Postfix version 2.1 and later:

       smtpd_sasl_exceptions_networks (empty)
              What  SMTP clients Postfix will not offer AUTH sup-
              port to.  STARTTLS SUPPORT CONTROLS
              Detailed information about  STARTTLS  configuration
              may be found in the TLS_README document.

       smtpd_use_tls (no)
              Opportunistic  mode:  announce  STARTTLS support to
              SMTP clients, but do not require that  clients  use
              TLS encryption.

       smtpd_enforce_tls (no)
              Enforcement mode: announce STARTTLS support to SMTP
              clients, and require that clients use  TLS  encryp-
              tion.

       smtpd_sasl_tls_security_options         ($smtpd_sasl_secu-
       rity_options)
              The  SASL  authentication security options that the
              Postfix SMTP server uses  for  TLS  encrypted  SMTP
              sessions.

       smtpd_starttls_timeout (300s)
              The  time  limit  for Postfix SMTP server write and
              read operations during  TLS  startup  and  shutdown
              handshake procedures.

       smtpd_tls_CAfile (empty)
              The  file with the certificate of the certification
              authority (CA) that issued the Postfix SMTP  server
              certificate.

       smtpd_tls_CAfile (empty)
              The  file with the certificate of the certification
              authority (CA) that issued the Postfix SMTP  server
              certificate.

       smtpd_tls_ask_ccert (no)
              Ask  a remote SMTP client for a client certificate.

       smtpd_tls_auth_only (no)
              When TLS encryption is optional in the Postfix SMTP
              server,  do not announce or accept SASL authentica-
              tion over unencrypted connections.

       smtpd_tls_ccert_verifydepth (5)
              The verification depth for remote SMTP client  cer-
              tificates.

       smtpd_tls_cert_file (empty)
              File  with  the Postfix SMTP server RSA certificate
              in PEM format.

       smtpd_tls_cipherlist (empty)
              Controls the Postfix SMTP server TLS cipher  selec-
              tion scheme.

       smtpd_tls_dcert_file (empty)
              File  with  the Postfix SMTP server DSA certificate
              in PEM format.

       smtpd_tls_dh1024_param_file (empty)
              File with  DH  parameters  that  the  Postfix  SMTP
              server should use with EDH ciphers.

       smtpd_tls_dh512_param_file (empty)
              File  with  DH  parameters  that  the  Postfix SMTP
              server should use with EDH ciphers.

       smtpd_tls_dkey_file ($smtpd_tls_dcert_file)
              File with the Postfix SMTP server DSA  private  key
              in PEM format.

       smtpd_tls_key_file ($smtpd_tls_cert_file)
              File  with  the Postfix SMTP server RSA private key
              in PEM format.

       smtpd_tls_loglevel (0)
              Enable additional Postfix SMTP  server  logging  of
              TLS activity.

       smtpd_tls_received_header (no)
              Request  that  the  Postfix  SMTP  server  produces
              Received:  message headers that include information
              about  the protocol and cipher used, as well as the
              client CommonName  and  client  certificate  issuer
              CommonName.

       smtpd_tls_req_ccert (no)
              When  TLS  encryption is enforced, require a remote
              SMTP client certificate in order to allow TLS  con-
              nections to proceed.

       smtpd_tls_session_cache_database (empty)
              Name  of  the  file containing the optional Postfix
              SMTP server TLS session cache.

       smtpd_tls_session_cache_timeout (3600s)
              The expiration time of Postfix SMTP server TLS ses-
              sion cache information.

       smtpd_tls_wrappermode (no)
              Run  the  Postfix  SMTP  server in the non-standard
              "wrapper" mode, instead of using the STARTTLS  com-
              mand.

       tls_daemon_random_bytes (32)
              The  number  of pseudo-random bytes that an smtp(8)
              or smtpd(8) process  requests  from  the  tlsmgr(8)
              server  in order to seed its internal pseudo random
              number generator (PRNG).  VERP SUPPORT CONTROLS
              With VERP style delivery, each recipient of a  mes-
              sage receives a customized copy of the message with
              his/her own recipient address encoded in the  enve-
              lope   sender   address.    The   VERP_README  file
              describes configuration and  operation  details  of
              Postfix  support  for variable envelope return path
              addresses.  VERP style delivery is  requested  with
              the  SMTP  XVERP  command or with the "sendmail -V"
              command-line option and  is  available  in  Postfix
              version 1.1 and later.

       default_verp_delimiters (+=)
              The two default VERP delimiter characters.

       verp_delimiter_filter (-=+)
              The  characters  Postfix  accepts as VERP delimiter
              characters on the Postfix sendmail(1) command  line
              and in SMTP commands.

       Available in Postfix version 1.1 and 2.0:

       authorized_verp_clients ($mynetworks)
              What  SMTP clients are allowed to specify the XVERP
              command.

       Available in Postfix version 2.1 and later:

       smtpd_authorized_verp_clients ($authorized_verp_clients)
              What SMTP clients are allowed to specify the  XVERP
              command.  TROUBLE SHOOTING CONTROLS
              The  DEBUG_README  document  describes how to debug
              parts of the Postfix mail system. The methods  vary
              from  making  the  software log a lot of detail, to
              running some daemon processes under  control  of  a
              call tracer or debugger.

       debug_peer_level (2)
              The  increment  in  verbose  logging  level  when a
              remote client or server matches a  pattern  in  the
              debug_peer_list parameter.

       debug_peer_list (empty)
              Optional  list  of remote client or server hostname
              or network address patterns that cause the  verbose
              logging  level  to increase by the amount specified
              in $debug_peer_level.

       error_notice_recipient (postmaster)
              The recipient  of  postmaster  notifications  about
              mail  delivery  problems that are caused by policy,
              resource, software or protocol errors.

       notify_classes (resource, software)
              The list of error classes that are reported to  the
              postmaster.

       soft_bounce (no)
              Safety net to keep mail queued that would otherwise
              be returned to the sender.

       Available in Postfix version 2.1 and later:

       smtpd_authorized_xclient_hosts (empty)
              What SMTP clients are allowed to  use  the  XCLIENT
              feature.  KNOWN VERSUS UNKNOWN RECIPIENT CONTROLS
              As  of Postfix version 2.0, the SMTP server rejects
              mail for unknown recipients. This prevents the mail
              queue  from  clogging up with undeliverable MAILER-
              DAEMON messages.  Additional  information  on  this
              topic   is   in   the   LOCAL_RECIPIENT_README  and
              ADDRESS_CLASS_README documents.

       show_user_unknown_table_name (yes)
              Display the name of  the  recipient  table  in  the
              "User unknown" responses.

       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.

       Parameters concerning known/unknown local recipients:

       mydestination  ($myhostname,  localhost.$mydomain,  local-
       host)
              The  list  of  domains  that  are delivered via the
              $local_transport mail delivery transport.

       inet_interfaces (all)
              The network interface addresses that this mail sys-
              tem receives mail on.

       proxy_interfaces (empty)
              The network interface addresses that this mail sys-
              tem receives mail on by way of a proxy  or  network
              address translation unit.

       inet_protocols (ipv4)
              The  Internet protocols Postfix will attempt to use
              when making or accepting connections.

       local_recipient_maps             (proxy:unix:passwd.byname
       $alias_maps)
              Lookup tables with all names or addresses of  local
              recipients:  a  recipient address is local when its
              domain matches $mydestination, $inet_interfaces  or
              $proxy_interfaces.

       unknown_local_recipient_reject_code (550)
              The  numerical  Postfix  SMTP  server response code
              when   a   recipient   address   is   local,    and
              $local_recipient_maps  specifies  a  list of lookup
              tables that does not match the recipient.

       Parameters concerning known/unknown  recipients  of  relay
       destinations:

       relay_domains ($mydestination)
              What  destination  domains (and subdomains thereof)
              this system will relay mail to.

       relay_recipient_maps (empty)
              Optional lookup tables with all valid addresses  in
              the domains that match $relay_domains.

       unknown_relay_recipient_reject_code (550)
              The numerical Postfix SMTP server reply code when a
              recipient  address  matches   $relay_domains,   and
              relay_recipient_maps  specifies  a  list  of lookup
              tables that does not match the recipient address.

       Parameters concerning known/unknown recipients in  virtual
       alias domains:

       virtual_alias_domains ($virtual_alias_maps)
              Postfix is final destination for the specified list
              of virtual alias  domains,  that  is,  domains  for
              which  all  addresses  are  aliased to addresses in
              other local or remote domains.

       virtual_alias_maps ($virtual_maps)
              Optional lookup tables  that  alias  specific  mail
              addresses  or  domains  to  other  local  or remote
              address.

       unknown_virtual_alias_reject_code (550)
              The SMTP server reply code when a recipient address
              matches     $virtual_alias_domains,    and    $vir-
              tual_alias_maps specifies a list of  lookup  tables
              that does not match the recipient address.

       Parameters  concerning known/unknown recipients in virtual
       mailbox domains:

       virtual_mailbox_domains ($virtual_mailbox_maps)
              Postfix is final destination for the specified list
              of   domains;  mail  is  delivered  via  the  $vir-
              tual_transport mail delivery transport.

       virtual_mailbox_maps (empty)
              Optional lookup tables with all valid addresses  in
              the domains that match $virtual_mailbox_domains.

       unknown_virtual_mailbox_reject_code (550)
              The SMTP server reply code when a recipient address
              matches   $virtual_mailbox_domains,    and    $vir-
              tual_mailbox_maps specifies a list of lookup tables
              that  does  not  match   the   recipient   address.
              RESOURCE AND RATE CONTROLS
              The  following  parameters  limit resource usage by
              the  SMTP  server  and/or  control  client  request
              rates.

       line_length_limit (2048)
              Upon  input,  long lines are chopped up into pieces
              of at most this length; upon delivery,  long  lines
              are reconstructed.

       queue_minfree (0)
              The  minimal  amount  of free space in bytes in the
              queue file system that is needed to receive mail.

       message_size_limit (10240000)
              The maximal size in bytes of a  message,  including
              envelope information.

       smtpd_recipient_limit (1000)
              The  maximal  number of recipients that the Postfix
              SMTP server accepts per message delivery request.

       smtpd_timeout (300s)
              The time limit for sending a  Postfix  SMTP  server
              response  and  for  receiving  a remote SMTP client
              request.

       smtpd_history_flush_threshold (100)
              The maximal number of lines  in  the  Postfix  SMTP
              server  command  history  before it is flushed upon
              receipt of EHLO, RSET, or end of DATA.

       The per SMTP client connection count and request rate lim-
       its are implemented in co-operation with the anvil(8) ser-
       vice, and are available in Postfix version 2.2 and  later.

       smtpd_client_connection_count_limit (50)
              How  many  simultaneous  connections  any client is
              allowed to make to this service.

       smtpd_client_connection_rate_limit (0)
              The  maximal  number  of  connection  attempts  any
              client  is allowed to make to this service per time
              unit.

       smtpd_client_message_rate_limit (0)
              The maximal number  of  message  delivery  requests
              that  any client is allowed to make to this service
              per time unit, regardless of whether or not Postfix
              actually accepts those messages.

       smtpd_client_recipient_rate_limit (0)
              The  maximal number of recipient addresses that any
              client is allowed to send to this service per  time
              unit, regardless of whether or not Postfix actually
              accepts those recipients.

       smtpd_client_event_limit_exceptions ($mynetworks)
              Clients that are excluded  from  connection  count,
              connection rate, or SMTP request rate restrictions.
              TARPIT CONTROLS
              When a remote SMTP client makes errors, the Postfix
              SMTP  server  can  insert delays before responding.
              This can help to slow down run-away software.   The
              behavior  is  controlled  by  an error counter that
              counts the number of errors within an SMTP  session
              that a client makes without delivering mail.

       smtpd_error_sleep_time (1s)
              With   Postfix  2.1  and  later:  the  SMTP  server
              response delay after a client has  made  more  than
              $smtpd_soft_error_limit   errors,  and  fewer  than
              $smtpd_hard_error_limit errors, without  delivering
              mail.

       smtpd_soft_error_limit (10)
              The  number  of  errors  a  remote  SMTP  client is
              allowed to make without delivering mail before  the
              Postfix SMTP server slows down all its responses.

       smtpd_hard_error_limit (20)
              The  maximal  number of errors a remote SMTP client
              is allowed to make without delivering mail.

       smtpd_junk_command_limit (100)
              The number of junk commands (NOOP,  VRFY,  ETRN  or
              RSET) that a remote SMTP client can send before the
              Postfix SMTP server starts to increment  the  error
              counter with each junk command.

       Available in Postfix version 2.1 and later:

       smtpd_recipient_overshoot_limit (1000)
              The  number of recipients that a remote SMTP client
              can send in excess  of  the  limit  specified  with
              $smtpd_recipient_limit,  before  the  Postfix  SMTP
              server increments the per-session error  count  for
              each  excess  recipient.   ACCESS POLICY DELEGATION
              CONTROLS
              As of version 2.1, Postfix  can  be  configured  to
              delegate  access  policy  decisions  to an external
              server that runs outside  Postfix.   See  the  file
              SMTPD_POLICY_README for more information.

       smtpd_policy_service_max_idle (300s)
              The  time  after which an idle SMTPD policy service
              connection is closed.

       smtpd_policy_service_max_ttl (1000s)
              The time after which an active SMTPD policy service
              connection is closed.

       smtpd_policy_service_timeout (100s)
              The  time  limit  for  connecting to, writing to or
              receiving from a  delegated  SMTPD  policy  server.
              ACCESS CONTROLS
              The SMTPD_ACCESS_README document gives an introduc-
              tion to all the SMTP  server  access  control  fea-
              tures.

       smtpd_delay_reject (yes)
              Wait  until  the  RCPT TO command before evaluating
              $smtpd_client_restrictions,    $smtpd_helo_restric-
              tions and $smtpd_sender_restrictions, or wait until
              the     ETRN     command     before      evaluating
              $smtpd_client_restrictions and $smtpd_helo_restric-
              tions.

       parent_domain_matches_subdomains (see 'postconf  -d'  out-
       put)
              What   Postfix   features   match   subdomains   of
              "domain.tld" automatically, instead of requiring an
              explicit ".domain.tld" pattern.

       smtpd_client_restrictions (empty)
              Optional SMTP server  access  restrictions  in  the
              context of a client SMTP connection request.

       smtpd_helo_required (no)
              Require that a remote SMTP client introduces itself
              at the beginning of an SMTP session with  the  HELO
              or EHLO command.

       smtpd_helo_restrictions (empty)
              Optional  restrictions that the Postfix SMTP server
              applies in the context of the SMTP HELO command.

       smtpd_sender_restrictions (empty)
              Optional restrictions that the Postfix SMTP  server
              applies in the context of the MAIL FROM command.

       smtpd_recipient_restrictions           (permit_mynetworks,
       reject_unauth_destination)
              The  access  restrictions  that  the  Postfix  SMTP
              server applies in the context of the RCPT  TO  com-
              mand.

       smtpd_etrn_restrictions (empty)
              Optional  SMTP  server  access  restrictions in the
              context of a client ETRN request.

       allow_untrusted_routing (no)
              Forward   mail   with   sender-specified    routing
              (user[@%!]remote[@%!]site)  from  untrusted clients
              to destinations matching $relay_domains.

       smtpd_restriction_classes (empty)
              User-defined aliases for groups of access  restric-
              tions.

       smtpd_null_access_lookup_key (<>)
              The  lookup key to be used in SMTP access(5) tables
              instead of the null sender address.

       permit_mx_backup_networks (empty)
              Restrict  the  use  of  the  permit_mx_backup  SMTP
              access  feature  to  only  domains whose primary MX
              hosts match the listed networks.

       Available in Postfix version 2.0 and later:

       smtpd_data_restrictions (empty)
              Optional access restrictions that the Postfix  SMTP
              server applies in the context of the SMTP DATA com-
              mand.

       smtpd_expansion_filter (see 'postconf -d' output)
              What characters are allowed in $name expansions  of
              RBL reply templates.

       Available in Postfix version 2.1 and later:

       smtpd_reject_unlisted_sender (no)
              Request  that  the Postfix SMTP server rejects mail
              from  unknown  sender  addresses,  even   when   no
              explicit  reject_unlisted_sender access restriction
              is specified.

       smtpd_reject_unlisted_recipient (yes)
              Request that the Postfix SMTP server  rejects  mail
              for  unknown  recipient  addresses,  even  when  no
              explicit reject_unlisted_recipient access  restric-
              tion is specified.

       Available in Postfix version 2.2 and later:

       smtpd_end_of_data_restrictions (empty)
              Optional  access restrictions that the Postfix SMTP
              server applies in the context of the  SMTP  END-OF-
              DATA command.  SENDER AND RECIPIENT ADDRESS VERIFI-
              CATION CONTROLS
              Postfix version 2.1 introduces sender and recipient
              address  verification.  This feature is implemented
              by sending probe email messages that are not  actu-
              ally  delivered.  This feature is requested via the
              reject_unverified_sender     and     reject_unveri-
              fied_recipient  access restrictions.  The status of
              verification probes is maintained by the  verify(8)
              server.   See  the file ADDRESS_VERIFICATION_README
              for information about how to configure and  operate
              the  Postfix  sender/recipient address verification
              service.

       address_verify_poll_count (3)
              How many times to query the verify(8)  service  for
              the  completion  of an address verification request
              in progress.

       address_verify_poll_delay (3s)
              The delay between queries for the completion of  an
              address verification request in progress.

       address_verify_sender (postmaster)
              The  sender  address to use in address verification
              probes.

       unverified_sender_reject_code (450)
              The numerical Postfix  SMTP  server  response  code
              when   a  recipient  address  is  rejected  by  the
              reject_unverified_sender restriction.

       unverified_recipient_reject_code (450)
              The numerical Postfix SMTP server response  when  a
              recipient address is rejected by the reject_unveri-
              fied_recipient   restriction.     ACCESS    CONTROL
              RESPONSES
              The  following  parameters  control  numerical SMTP
              reply codes and/or text responses.

       access_map_reject_code (554)
              The numerical Postfix  SMTP  server  response  code
              when  a  client  is  rejected  by  an access(5) map
              restriction.

       defer_code (450)
              The numerical Postfix  SMTP  server  response  code
              when  a  remote  SMTP client request is rejected by
              the "defer" restriction.

       invalid_hostname_reject_code (501)
              The numerical Postfix  SMTP  server  response  code
              when  the  client HELO or EHLO command parameter is
              rejected by  the  reject_invalid_hostname  restric-
              tion.

       maps_rbl_reject_code (554)
              The  numerical  Postfix  SMTP  server response code
              when a remote SMTP client request is blocked by the
              reject_rbl_client,             reject_rhsbl_client,
              reject_rhsbl_sender    or    reject_rhsbl_recipient
              restriction.

       non_fqdn_reject_code (504)
              The numerical Postfix SMTP server reply code when a
              client    request    is     rejected     by     the
              reject_non_fqdn_hostname, reject_non_fqdn_sender or
              reject_non_fqdn_recipient restriction.

       reject_code (554)
              The numerical Postfix  SMTP  server  response  code
              when  a  remote  SMTP client request is rejected by
              the "reject" restriction.

       relay_domains_reject_code (554)
              The numerical Postfix  SMTP  server  response  code
              when   a   client   request   is  rejected  by  the
              reject_unauth_destination recipient restriction.

       unknown_address_reject_code (450)
              The numerical Postfix  SMTP  server  response  code
              when  a  sender or recipient address is rejected by
              the         reject_unknown_sender_domain         or
              reject_unknown_recipient_domain restriction.

       unknown_client_reject_code (450)
              The  numerical  Postfix  SMTP  server response code
              when a client without valid address <=>  name  map-
              ping   is  rejected  by  the  reject_unknown_client
              restriction.

       unknown_hostname_reject_code (450)
              The numerical Postfix  SMTP  server  response  code
              when  the  hostname specified with the HELO or EHLO
              command is rejected by the  reject_unknown_hostname
              restriction.

       Available in Postfix version 2.0 and later:

       default_rbl_reply (see 'postconf -d' output)
              The  default  SMTP  server  response template for a
              request that is rejected by an  RBL-based  restric-
              tion.

       multi_recipient_bounce_reject_code (550)
              The  numerical  Postfix  SMTP  server response code
              when a remote SMTP client request is blocked by the
              reject_multi_recipient_bounce restriction.

       rbl_reply_maps (empty)
              Optional lookup tables with RBL response templates.
              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.

       command_directory (see 'postconf -d' output)
              The  location  of  all  postfix administrative com-
              mands.

       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.

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

       mail_owner (postfix)
              The UNIX system account that owns the Postfix queue
              and most Postfix daemon processes.

       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.

       myhostname (see 'postconf -d' output)
              The internet hostname of this mail system.

       mynetworks (see 'postconf -d' output)
              The list of "trusted" SMTP clients that  have  more
              privileges than "strangers".

       myorigin ($myhostname)
              The domain name that locally-posted mail appears to
              come from, and that locally posted mail  is  deliv-
              ered 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 direc-
              tory.

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

       smtpd_banner ($myhostname ESMTP $mail_name)
              The  text  that  follows the 220 status code in the
              SMTP greeting banner.

       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".

       Available in Postfix version 2.2 and later:

       smtpd_forbidden_commands (CONNECT, GET, POST)
              List of  commands  that  causes  the  Postfix  SMTP
              server  to immediately terminate the session with a
              221 code.  SEE ALSO anvil(8), connection/rate  lim-
              iting    cleanup(8),    message    canonicalization
              tlsmgr(8), TLS session and PRNG management trivial-
              rewrite(8),  address  resolver  verify(8),  address
              verification  service  postconf(5),   configuration
              parameters  master(5),  generic daemon options mas-
              ter(8), process manager syslogd(8), system  logging
              README FILES
              Use   "postconf   readme_directory"   or  "postconf
              html_directory" to locate this information.
              ADDRESS_CLASS_README, blocking unknown hosted or relay recipients
              ADDRESS_REWRITING_README Postfix address manipulation
              FILTER_README, external after-queue content filter
              LOCAL_RECIPIENT_README, blocking unknown local recipients
              SMTPD_ACCESS_README, built-in access policies
              SMTPD_POLICY_README, external policy server
              SMTPD_PROXY_README, external before-queue content filter
              SASL_README, Postfix SASL howto
              TLS_README, Postfix STARTTLS howto
              VERP_README, Postfix XVERP extension
              XCLIENT_README, Postfix XCLIENT extension
              XFORWARD_README, Postfix XFORWARD extension
              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

              TLS  support  originally by: Lutz Jaenicke BTU Cot-
              tbus Allgemeine  Elektrotechnik  Universitaetsplatz
              3-4 D-03044 Cottbus, Germany

                                                                      SMTPD(8)