SMTPD(8)                                                              SMTPD(8)

NAME
       smtpd  -  Postfix  SMTP  server  SYNOPSIS smtpd [generic Postfix 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) daemon, and is placed  into  the  incoming
       queue  as  one single queue file.  For this mode of operation, the pro-
       gram expects to be run from the master(8) process manager.

       Alternatively, the SMTP server takes an established connection on stan-
       dard  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 connection
       requests, and for parameters given to HELO, ETRN, MAIL FROM,  VRFY  and
       RCPT TO commands. They are detailed below and in the main.cf configura-
       tion 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 requirements) RFC 1652 (8bit-MIME transport) RFC 1869 (SMTP
       service extensions) RFC 1870 (Message Size Declaration) RFC 1985  (ETRN
       command)  RFC  2554  (AUTH  command)  RFC 2821 (SMTP protocol) RFC 2920
       (SMTP Pipelining)

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

       Depending on the setting of the notify_classes parameter, the  postmas-
       ter  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.  COMPATIBILITY 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 comments 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 support to.  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  con-
              tent  filter  is expected to inject mail back into a (Postfix or
              other) MTA for further delivery. See the FILTER_README  document
              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 docu-
              ment 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  fil-
              ter.

       smtpd_proxy_timeout (100s)
              The  time limit for connecting to a proxy filter and for sending
              or receiving information.  GENERAL CONTENT 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 filter-
              ing, or address rewriting.  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 authenti-
              cate  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 initialization.

       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.

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

       smtpd_sasl_path (empty)
              The path where SASL will look for plugins. This is a colon sepa-
              rated 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 support to.   VERP
              SUPPORT CONTROLS
              With VERP style delivery, each recipient of a message receives a
              customized copy  of  the  message  with  his/her  own  recipient
              address encoded in the envelope 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 con-
              trol 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 proto-
              col 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  infor-
              mation  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, localhost)
              The  list of domains that are delivered via the $local_transport
              mail delivery transport.

       inet_interfaces (all)
              The network interface addresses that this mail  system  receives
              mail on.

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

       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 $mydestina-
              tion, $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 speci-
              fies 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)
              Optional list of  names  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 $virtual_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)
              The list of domains that are delivered via  the  $virtual_trans-
              port 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 $virtual_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 sys-
              tem 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.

       Not available in Postfix version 2.1:

       smtpd_client_connection_count_limit (50)
              How  many simultaneous connections any SMTP client is allowed to
              make to the SMTP 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_connection_limit_exceptions ($mynetworks)
              Clients  that  are  excluded from connection count or connection
              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 CON-
              TROLS
              As of version 2.1, Postfix can be configured to delegate  access
              policy  decisions  to an external server that runs outside Post-
              fix.  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 introduction to all
              the SMTP server access control features.

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

       parent_domain_matches_subdomains (see 'postconf -d' output)
              What Postfix features match subdomains of "domain.tld" automati-
              cally, 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_destina-
       tion)
              The  access restrictions that the Postfix SMTP server applies in
              the context of the RCPT TO command.

       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  destina-
              tions matching $relay_domains.

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

       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 command.

       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   restriction  is  specified.
              SENDER AND RECIPIENT ADDRESS VERIFICATION CONTROLS
              Postfix version 2.1 introduces sender and recipient address ver-
              ification.   This  feature is implemented by sending probe email
              messages that are  not  actually  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 config-
              ure  and  operate the Postfix sender/recipient address verifica-
              tion 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 veri-
              fication 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_unverified_recipient restric-
              tion.  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 restriction.

       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_recipi-
              ent 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  mapping  is  rejected  by  the
              reject_unknown_client restriction.

       unknown_hostname_reject_code (450)
              The  numerical  Postfix SMTP server response code when the host-
              name 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 restriction.

       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_recipi-
              ent_bounce restriction.

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

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

       double_bounce_sender (double-bounce)
              The  sender  address of postmaster notifications that are gener-
              ated 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  dae-
              mon 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 delivered to.

       process_id (read-only)
              The process ID of a Postfix command or daemon process.

       process_name (read-only)
              The process name of a Postfix command or daemon process.

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

       recipient_delimiter (empty)
              The   separator   between  user  names  and  address  extensions
              (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,  "post-
              fix/smtpd".  SEE ALSO cleanup(8), message canonicalization triv-
              ial-rewrite(8), address resolver verify(8), address verification
              service postconf(5), configuration parameters master(8), process
              manager syslogd(8), system logging README FILES
              locate this information.
              ADDRESS_CLASS_README, blocking unknown hosted or relay recipients
              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
              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 soft-
              ware.  AUTHOR(S) Wietse Venema IBM T.J. Watson Research P.O. Box
              704 Yorktown Heights, NY 10598, USA

                                                                      SMTPD(8)