postfix-master/smtpd.8.html

   1 <!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
   2         "http://www.w3.org/TR/html4/loose.dtd">
   3 <html> <head>
   4 <meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
   5 <title> Postfix manual - smtpd(8) </title>
   6 </head> <body> <pre>
   7 SMTPD(8)                                                              SMTPD(8)
   8
   9 <b>NAME</b>
  10        smtpd - Postfix SMTP server
  11
  12 <b>SYNOPSIS</b>
  13        <b>smtpd</b> [generic Postfix daemon options]
  14
  15        <b>sendmail -bs</b>
  16
  17 <b>DESCRIPTION</b>
  18        The  SMTP  server  accepts network connection requests and
  19        performs zero or more SMTP  transactions  per  connection.
  20        Each received message is piped through the <a href="cleanup.8.html"><b>cleanup</b>(8)</a> dae-
  21        mon, and is placed into the <a href="QSHAPE_README.html#incoming_queue"><b>incoming</b> queue</a> as  one  single
  22        queue  file.   For  this  mode  of  operation, the program
  23        expects to be run from the <a href="master.8.html"><b>master</b>(8)</a> process manager.
  24
  25        Alternatively, the SMTP server be can run  in  stand-alone
  26        mode;  this is traditionally obtained with "<b>sendmail -bs</b>".
  27        When the SMTP server runs stand-alone with non $<b><a href="postconf.5.html#mail_owner">mail_owner</a></b>
  28        privileges, it receives mail even while the mail system is
  29        not running, deposits messages directly into the  <b>maildrop</b>
  30        queue,  and disables the SMTP server's access policies. As
  31        of Postfix version 2.3, the SMTP server refuses to receive
  32        mail  from  the  network when it runs with non $<b><a href="postconf.5.html#mail_owner">mail_owner</a></b>
  33        privileges.
  34
  35        The SMTP server implements a variety of policies for  con-
  36        nection  requests, and for parameters given to <b>HELO, ETRN,</b>
  37        <b>MAIL FROM, VRFY</b> and <b>RCPT TO</b> commands.  They  are  detailed
  38        below and in the <a href="postconf.5.html"><b>main.cf</b></a> configuration file.
  39
  40 <b>SECURITY</b>
  41        The SMTP server is moderately security-sensitive. It talks
  42        to SMTP clients and to DNS servers  on  the  network.  The
  43        SMTP server can be run chrooted at fixed low privilege.
  44
  45 <b>STANDARDS</b>
  46        <a href="http://tools.ietf.org/html/rfc821">RFC 821</a> (SMTP protocol)
  47        <a href="http://tools.ietf.org/html/rfc1123">RFC 1123</a> (Host requirements)
  48        <a href="http://tools.ietf.org/html/rfc1652">RFC 1652</a> (8bit-MIME transport)
  49        <a href="http://tools.ietf.org/html/rfc1869">RFC 1869</a> (SMTP service extensions)
  50        <a href="http://tools.ietf.org/html/rfc1870">RFC 1870</a> (Message Size Declaration)
  51        <a href="http://tools.ietf.org/html/rfc1985">RFC 1985</a> (ETRN command)
  52        <a href="http://tools.ietf.org/html/rfc2034">RFC 2034</a> (SMTP Enhanced Status Codes)
  53        <a href="http://tools.ietf.org/html/rfc2554">RFC 2554</a> (AUTH command)
  54        <a href="http://tools.ietf.org/html/rfc2821">RFC 2821</a> (SMTP protocol)
  55        <a href="http://tools.ietf.org/html/rfc2920">RFC 2920</a> (SMTP Pipelining)
  56        <a href="http://tools.ietf.org/html/rfc3207">RFC 3207</a> (STARTTLS command)
  57        <a href="http://tools.ietf.org/html/rfc3461">RFC 3461</a> (SMTP DSN Extension)
  58        <a href="http://tools.ietf.org/html/rfc3463">RFC 3463</a> (Enhanced Status Codes)
  59        <a href="http://tools.ietf.org/html/rfc3848">RFC 3848</a> (ESMTP Transmission Types)
  60        <a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a> (AUTH command)
  61
  62 <b>DIAGNOSTICS</b>
  63        Problems and transactions are logged to <b>syslogd</b>(8).
  64
  65        Depending  on the setting of the <b><a href="postconf.5.html#notify_classes">notify_classes</a></b> parameter,
  66        the postmaster is notified of bounces, protocol  problems,
  67        policy violations, and of other trouble.
  68
  69 <b>CONFIGURATION PARAMETERS</b>
  70        Changes   to  <a href="postconf.5.html"><b>main.cf</b></a>  are  picked  up  automatically,  as
  71        <a href="smtpd.8.html"><b>smtpd</b>(8)</a> processes run for only a limited amount of  time.
  72        Use the command "<b>postfix reload</b>" to speed up a change.
  73
  74        The  text  below  provides  only  a parameter summary. See
  75        <a href="postconf.5.html"><b>postconf</b>(5)</a> for more details including examples.
  76
  77 <b>COMPATIBILITY CONTROLS</b>
  78        The following parameters work around implementation errors
  79        in  other software, and/or allow you to override standards
  80        in order to prevent undesirable use.
  81
  82        <b><a href="postconf.5.html#broken_sasl_auth_clients">broken_sasl_auth_clients</a> (no)</b>
  83               Enable inter-operability  with  SMTP  clients  that
  84               implement  an  obsolete version of the AUTH command
  85               (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>).
  86
  87        <b><a href="postconf.5.html#disable_vrfy_command">disable_vrfy_command</a> (no)</b>
  88               Disable the SMTP VRFY command.
  89
  90        <b><a href="postconf.5.html#smtpd_noop_commands">smtpd_noop_commands</a> (empty)</b>
  91               List of  commands  that  the  Postfix  SMTP  server
  92               replies  to with "250 Ok", without doing any syntax
  93               checks and without changing state.
  94
  95        <b><a href="postconf.5.html#strict_rfc821_envelopes">strict_rfc821_envelopes</a> (no)</b>
  96               Require that addresses received in SMTP  MAIL  FROM
  97               and RCPT TO commands are enclosed with &lt;&gt;, and that
  98               those addresses do not contain <a href="http://tools.ietf.org/html/rfc822">RFC 822</a>  style  com-
  99               ments or phrases.
 100
 101        Available in Postfix version 2.1 and later:
 102
 103        <b><a href="postconf.5.html#resolve_null_domain">resolve_null_domain</a> (no)</b>
 104               Resolve an address that ends in the "@" null domain
 105               as if the local hostname were specified, instead of
 106               rejecting the address as invalid.
 107
 108        <b><a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> (no)</b>
 109               Request  that  the Postfix SMTP server rejects mail
 110               from  unknown  sender  addresses,  even   when   no
 111               explicit  <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a> access restriction
 112               is specified.
 113
 114        <b><a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> (empty)</b>
 115               What remote SMTP clients the  Postfix  SMTP  server
 116               will not offer AUTH support to.
 117
 118        Available in Postfix version 2.2 and later:
 119
 120        <b><a href="postconf.5.html#smtpd_discard_ehlo_keyword_address_maps">smtpd_discard_ehlo_keyword_address_maps</a> (empty)</b>
 121               Lookup  tables,  indexed  by the remote SMTP client
 122               address, with case insensitive lists of  EHLO  key-
 123               words  (pipelining,  starttls, auth, etc.) that the
 124               SMTP server will not send in the EHLO response to a
 125               remote SMTP client.
 126
 127        <b><a href="postconf.5.html#smtpd_discard_ehlo_keywords">smtpd_discard_ehlo_keywords</a> (empty)</b>
 128               A  case insensitive list of EHLO keywords (pipelin-
 129               ing, starttls, auth, etc.)  that  the  SMTP  server
 130               will not send in the EHLO response to a remote SMTP
 131               client.
 132
 133        <b><a href="postconf.5.html#smtpd_delay_open_until_valid_rcpt">smtpd_delay_open_until_valid_rcpt</a> (yes)</b>
 134               Postpone the start  of  an  SMTP  mail  transaction
 135               until a valid RCPT TO command is received.
 136
 137        Available in Postfix version 2.3 and later:
 138
 139        <b><a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> (yes)</b>
 140               Force  the  Postfix SMTP server to issue a TLS ses-
 141               sion id, even when TLS session  caching  is  turned
 142               off (<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> is empty).
 143
 144        Available in Postfix version 2.6 and later:
 145
 146        <b><a href="postconf.5.html#tcp_windowsize">tcp_windowsize</a> (0)</b>
 147               An  optional  workaround for routers that break TCP
 148               window scaling.
 149
 150        Available in Postfix version 2.7 and later:
 151
 152        <b><a href="postconf.5.html#smtpd_command_filter">smtpd_command_filter</a> (empty)</b>
 153               A mechanism to transform commands from remote  SMTP
 154               clients.
 155
 156        Available in Postfix version 2.9 and later:
 157
 158        <b><a href="postconf.5.html#smtpd_per_record_deadline">smtpd_per_record_deadline</a> (normal: no, overload: yes)</b>
 159               Change  the  behavior  of  the  <a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a>  time
 160               limit, from a time limit per read or  write  system
 161               call, to a time limit to send or receive a complete
 162               record (an SMTP command line, SMTP  response  line,
 163               SMTP  message  content  line,  or TLS protocol mes-
 164               sage).
 165
 166 <b>ADDRESS REWRITING CONTROLS</b>
 167        See the <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> document for  a  detailed
 168        discussion of Postfix address rewriting.
 169
 170        <b><a href="postconf.5.html#receive_override_options">receive_override_options</a> (empty)</b>
 171               Enable  or  disable  recipient validation, built-in
 172               content filtering, or address mapping.
 173
 174        Available in Postfix version 2.2 and later:
 175
 176        <b><a href="postconf.5.html#local_header_rewrite_clients">local_header_rewrite_clients</a> (<a href="postconf.5.html#permit_inet_interfaces">permit_inet_interfaces</a>)</b>
 177               Rewrite message header addresses in mail from these
 178               clients  and  update  incomplete addresses with the
 179               domain name in $<a href="postconf.5.html#myorigin">myorigin</a> or $<a href="postconf.5.html#mydomain">mydomain</a>; either don't
 180               rewrite  message headers from other clients at all,
 181               or rewrite message headers  and  update  incomplete
 182               addresses   with   the   domain  specified  in  the
 183               <a href="postconf.5.html#remote_header_rewrite_domain">remote_header_rewrite_domain</a> parameter.
 184
 185 <b>AFTER QUEUE EXTERNAL CONTENT INSPECTION CONTROLS</b>
 186        As of version 1.0, Postfix can be configured to  send  new
 187        mail  to  an  external  content  filter  AFTER the mail is
 188        queued. This content filter is  expected  to  inject  mail
 189        back  into  a (Postfix or other) MTA for further delivery.
 190        See the <a href="FILTER_README.html">FILTER_README</a> document for details.
 191
 192        <b><a href="postconf.5.html#content_filter">content_filter</a> (empty)</b>
 193               After the message is queued, send the  entire  mes-
 194               sage to the specified <i>transport:destination</i>.
 195
 196 <b>BEFORE QUEUE EXTERNAL CONTENT INSPECTION CONTROLS</b>
 197        As  of version 2.1, the Postfix SMTP server can be config-
 198        ured to send incoming mail to a real-time SMTP-based  con-
 199        tent filter BEFORE mail is queued.  This content filter is
 200        expected to  inject  mail  back  into  Postfix.   See  the
 201        <a href="SMTPD_PROXY_README.html">SMTPD_PROXY_README</a>  document for details on how to config-
 202        ure and operate this feature.
 203
 204        <b><a href="postconf.5.html#smtpd_proxy_filter">smtpd_proxy_filter</a> (empty)</b>
 205               The hostname and TCP port  of  the  mail  filtering
 206               proxy server.
 207
 208        <b><a href="postconf.5.html#smtpd_proxy_ehlo">smtpd_proxy_ehlo</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
 209               How the Postfix SMTP server announces itself to the
 210               proxy filter.
 211
 212        <b><a href="postconf.5.html#smtpd_proxy_options">smtpd_proxy_options</a> (empty)</b>
 213               List of options that control how the  Postfix  SMTP
 214               server  communicates  with  a  before-queue content
 215               filter.
 216
 217        <b><a href="postconf.5.html#smtpd_proxy_timeout">smtpd_proxy_timeout</a> (100s)</b>
 218               The time limit for connecting to a proxy filter and
 219               for sending or receiving information.
 220
 221 <b>BEFORE QUEUE MILTER CONTROLS</b>
 222        As of version 2.3, Postfix supports the Sendmail version 8
 223        Milter (mail filter) protocol. These content  filters  run
 224        outside  Postfix. They can inspect the SMTP command stream
 225        and the message content,  and  can  request  modifications
 226        before  mail  is queued. For details see the <a href="MILTER_README.html">MILTER_README</a>
 227        document.
 228
 229        <b><a href="postconf.5.html#smtpd_milters">smtpd_milters</a> (empty)</b>
 230               A list of Milter (mail filter) applications for new
 231               mail  that arrives via the Postfix <a href="smtpd.8.html"><b>smtpd</b>(8)</a> server.
 232
 233        <b><a href="postconf.5.html#milter_protocol">milter_protocol</a> (6)</b>
 234               The mail filter protocol version and optional  pro-
 235               tocol  extensions  for  communication with a Milter
 236               application; prior to Postfix 2.6 the default  pro-
 237               tocol is 2.
 238
 239        <b><a href="postconf.5.html#milter_default_action">milter_default_action</a> (tempfail)</b>
 240               The  default  action  when  a  Milter (mail filter)
 241               application is unavailable or mis-configured.
 242
 243        <b><a href="postconf.5.html#milter_macro_daemon_name">milter_macro_daemon_name</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
 244               The {daemon_name} macro value for Milter (mail fil-
 245               ter) applications.
 246
 247        <b><a href="postconf.5.html#milter_macro_v">milter_macro_v</a> ($<a href="postconf.5.html#mail_name">mail_name</a> $<a href="postconf.5.html#mail_version">mail_version</a>)</b>
 248               The {v} macro value for Milter (mail filter) appli-
 249               cations.
 250
 251        <b><a href="postconf.5.html#milter_connect_timeout">milter_connect_timeout</a> (30s)</b>
 252               The time limit for connecting  to  a  Milter  (mail
 253               filter)  application,  and for negotiating protocol
 254               options.
 255
 256        <b><a href="postconf.5.html#milter_command_timeout">milter_command_timeout</a> (30s)</b>
 257               The time limit for sending an  SMTP  command  to  a
 258               Milter (mail filter) application, and for receiving
 259               the response.
 260
 261        <b><a href="postconf.5.html#milter_content_timeout">milter_content_timeout</a> (300s)</b>
 262               The time limit for sending  message  content  to  a
 263               Milter (mail filter) application, and for receiving
 264               the response.
 265
 266        <b><a href="postconf.5.html#milter_connect_macros">milter_connect_macros</a> (see 'postconf -d' output)</b>
 267               The macros that are sent to  Milter  (mail  filter)
 268               applications  after  completion  of an SMTP connec-
 269               tion.
 270
 271        <b><a href="postconf.5.html#milter_helo_macros">milter_helo_macros</a> (see 'postconf -d' output)</b>
 272               The macros that are sent to  Milter  (mail  filter)
 273               applications after the SMTP HELO or EHLO command.
 274
 275        <b><a href="postconf.5.html#milter_mail_macros">milter_mail_macros</a> (see 'postconf -d' output)</b>
 276               The  macros  that  are sent to Milter (mail filter)
 277               applications after the SMTP MAIL FROM command.
 278
 279        <b><a href="postconf.5.html#milter_rcpt_macros">milter_rcpt_macros</a> (see 'postconf -d' output)</b>
 280               The macros that are sent to  Milter  (mail  filter)
 281               applications after the SMTP RCPT TO command.
 282
 283        <b><a href="postconf.5.html#milter_data_macros">milter_data_macros</a> (see 'postconf -d' output)</b>
 284               The  macros  that  are  sent to version 4 or higher
 285               Milter (mail filter) applications  after  the  SMTP
 286               DATA command.
 287
 288        <b><a href="postconf.5.html#milter_unknown_command_macros">milter_unknown_command_macros</a> (see 'postconf -d' output)</b>
 289               The  macros  that  are  sent to version 3 or higher
 290               Milter (mail filter) applications after an  unknown
 291               SMTP command.
 292
 293        <b><a href="postconf.5.html#milter_end_of_header_macros">milter_end_of_header_macros</a> (see 'postconf -d' output)</b>
 294               The  macros  that  are sent to Milter (mail filter)
 295               applications after the end of the message header.
 296
 297        <b><a href="postconf.5.html#milter_end_of_data_macros">milter_end_of_data_macros</a> (see 'postconf -d' output)</b>
 298               The macros that are sent to  Milter  (mail  filter)
 299               applications after the message end-of-data.
 300
 301 <b>GENERAL CONTENT INSPECTION CONTROLS</b>
 302        The  following parameters are applicable for both built-in
 303        and external content filters.
 304
 305        Available in Postfix version 2.1 and later:
 306
 307        <b><a href="postconf.5.html#receive_override_options">receive_override_options</a> (empty)</b>
 308               Enable or disable  recipient  validation,  built-in
 309               content filtering, or address mapping.
 310
 311 <b>EXTERNAL CONTENT INSPECTION CONTROLS</b>
 312        The  following  parameters are applicable for both before-
 313        queue and after-queue content filtering.
 314
 315        Available in Postfix version 2.1 and later:
 316
 317        <b><a href="postconf.5.html#smtpd_authorized_xforward_hosts">smtpd_authorized_xforward_hosts</a> (empty)</b>
 318               What SMTP clients are allowed to use  the  XFORWARD
 319               feature.
 320
 321 <b>SASL AUTHENTICATION CONTROLS</b>
 322        Postfix  SASL  support (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>) can be used to authenti-
 323        cate remote SMTP clients to the Postfix SMTP  server,  and
 324        to  authenticate  the Postfix SMTP client to a remote SMTP
 325        server.  See the <a href="SASL_README.html">SASL_README</a> document for details.
 326
 327        <b><a href="postconf.5.html#broken_sasl_auth_clients">broken_sasl_auth_clients</a> (no)</b>
 328               Enable inter-operability  with  SMTP  clients  that
 329               implement  an  obsolete version of the AUTH command
 330               (<a href="http://tools.ietf.org/html/rfc4954">RFC 4954</a>).
 331
 332        <b><a href="postconf.5.html#smtpd_sasl_auth_enable">smtpd_sasl_auth_enable</a> (no)</b>
 333               Enable SASL  authentication  in  the  Postfix  SMTP
 334               server.
 335
 336        <b><a href="postconf.5.html#smtpd_sasl_local_domain">smtpd_sasl_local_domain</a> (empty)</b>
 337               The  name  of  the Postfix SMTP server's local SASL
 338               authentication realm.
 339
 340        <b><a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_security_options</a> (noanonymous)</b>
 341               Postfix SMTP server SASL security  options;  as  of
 342               Postfix  2.3 the list of available features depends
 343               on the SASL server implementation that is  selected
 344               with <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>.
 345
 346        <b><a href="postconf.5.html#smtpd_sender_login_maps">smtpd_sender_login_maps</a> (empty)</b>
 347               Optional  lookup  table  with  the SASL login names
 348               that own sender (MAIL FROM) addresses.
 349
 350        Available in Postfix version 2.1 and later:
 351
 352        <b><a href="postconf.5.html#smtpd_sasl_exceptions_networks">smtpd_sasl_exceptions_networks</a> (empty)</b>
 353               What remote SMTP clients the  Postfix  SMTP  server
 354               will not offer AUTH support to.
 355
 356        Available in Postfix version 2.1 and 2.2:
 357
 358        <b><a href="postconf.5.html#smtpd_sasl_application_name">smtpd_sasl_application_name</a> (smtpd)</b>
 359               The  application  name that the Postfix SMTP server
 360               uses for SASL server initialization.
 361
 362        Available in Postfix version 2.3 and later:
 363
 364        <b><a href="postconf.5.html#smtpd_sasl_authenticated_header">smtpd_sasl_authenticated_header</a> (no)</b>
 365               Report the SASL  authenticated  user  name  in  the
 366               <a href="smtpd.8.html"><b>smtpd</b>(8)</a> Received message header.
 367
 368        <b><a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a> (smtpd)</b>
 369               Implementation-specific  information that the Post-
 370               fix SMTP server passes through to the SASL  plug-in
 371               implementation     that     is     selected    with
 372               <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a></b>.
 373
 374        <b><a href="postconf.5.html#smtpd_sasl_type">smtpd_sasl_type</a> (cyrus)</b>
 375               The SASL plug-in type that the Postfix SMTP  server
 376               should use for authentication.
 377
 378        Available in Postfix version 2.5 and later:
 379
 380        <b><a href="postconf.5.html#cyrus_sasl_config_path">cyrus_sasl_config_path</a> (empty)</b>
 381               Search  path  for Cyrus SASL application configura-
 382               tion files,  currently  used  only  to  locate  the
 383               $<a href="postconf.5.html#smtpd_sasl_path">smtpd_sasl_path</a>.conf file.
 384
 385 <b>STARTTLS SUPPORT CONTROLS</b>
 386        Detailed  information  about STARTTLS configuration may be
 387        found in the <a href="TLS_README.html">TLS_README</a> document.
 388
 389        <b><a href="postconf.5.html#smtpd_tls_security_level">smtpd_tls_security_level</a> (empty)</b>
 390               The SMTP TLS security level for  the  Postfix  SMTP
 391               server;  when  a non-empty value is specified, this
 392               overrides the obsolete parameters <a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> and
 393               <a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a>.
 394
 395        <b><a href="postconf.5.html#smtpd_sasl_tls_security_options">smtpd_sasl_tls_security_options</a>         ($<a href="postconf.5.html#smtpd_sasl_security_options">smtpd_sasl_secu</a>-</b>
 396        <b><a href="postconf.5.html#smtpd_sasl_security_options">rity_options</a>)</b>
 397               The  SASL  authentication security options that the
 398               Postfix SMTP server uses  for  TLS  encrypted  SMTP
 399               sessions.
 400
 401        <b><a href="postconf.5.html#smtpd_starttls_timeout">smtpd_starttls_timeout</a> (see 'postconf -d' output)</b>
 402               The  time  limit  for Postfix SMTP server write and
 403               read operations during  TLS  startup  and  shutdown
 404               handshake procedures.
 405
 406        <b><a href="postconf.5.html#smtpd_tls_CAfile">smtpd_tls_CAfile</a> (empty)</b>
 407               A  file  containing (PEM format) CA certificates of
 408               root CAs trusted to sign either remote SMTP  client
 409               certificates or intermediate CA certificates.
 410
 411        <b><a href="postconf.5.html#smtpd_tls_CApath">smtpd_tls_CApath</a> (empty)</b>
 412               A directory containing (PEM format) CA certificates
 413               of root CAs trusted  to  sign  either  remote  SMTP
 414               client  certificates  or  intermediate  CA certifi-
 415               cates.
 416
 417        <b><a href="postconf.5.html#smtpd_tls_always_issue_session_ids">smtpd_tls_always_issue_session_ids</a> (yes)</b>
 418               Force the Postfix SMTP server to issue a  TLS  ses-
 419               sion  id,  even  when TLS session caching is turned
 420               off (<a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> is empty).
 421
 422        <b><a href="postconf.5.html#smtpd_tls_ask_ccert">smtpd_tls_ask_ccert</a> (no)</b>
 423               Ask a remote SMTP client for a client  certificate.
 424
 425        <b><a href="postconf.5.html#smtpd_tls_auth_only">smtpd_tls_auth_only</a> (no)</b>
 426               When TLS encryption is optional in the Postfix SMTP
 427               server, do not announce or accept SASL  authentica-
 428               tion over unencrypted connections.
 429
 430        <b><a href="postconf.5.html#smtpd_tls_ccert_verifydepth">smtpd_tls_ccert_verifydepth</a> (9)</b>
 431               The  verification depth for remote SMTP client cer-
 432               tificates.
 433
 434        <b><a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a> (empty)</b>
 435               File with the Postfix SMTP server  RSA  certificate
 436               in PEM format.
 437
 438        <b><a href="postconf.5.html#smtpd_tls_exclude_ciphers">smtpd_tls_exclude_ciphers</a> (empty)</b>
 439               List of ciphers or cipher types to exclude from the
 440               SMTP server cipher list at all TLS security levels.
 441
 442        <b><a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a> (empty)</b>
 443               File  with  the Postfix SMTP server DSA certificate
 444               in PEM format.
 445
 446        <b><a href="postconf.5.html#smtpd_tls_dh1024_param_file">smtpd_tls_dh1024_param_file</a> (empty)</b>
 447               File with  DH  parameters  that  the  Postfix  SMTP
 448               server should use with EDH ciphers.
 449
 450        <b><a href="postconf.5.html#smtpd_tls_dh512_param_file">smtpd_tls_dh512_param_file</a> (empty)</b>
 451               File  with  DH  parameters  that  the  Postfix SMTP
 452               server should use with EDH ciphers.
 453
 454        <b><a href="postconf.5.html#smtpd_tls_dkey_file">smtpd_tls_dkey_file</a> ($<a href="postconf.5.html#smtpd_tls_dcert_file">smtpd_tls_dcert_file</a>)</b>
 455               File with the Postfix SMTP server DSA  private  key
 456               in PEM format.
 457
 458        <b><a href="postconf.5.html#smtpd_tls_key_file">smtpd_tls_key_file</a> ($<a href="postconf.5.html#smtpd_tls_cert_file">smtpd_tls_cert_file</a>)</b>
 459               File  with  the Postfix SMTP server RSA private key
 460               in PEM format.
 461
 462        <b><a href="postconf.5.html#smtpd_tls_loglevel">smtpd_tls_loglevel</a> (0)</b>
 463               Enable additional Postfix SMTP  server  logging  of
 464               TLS activity.
 465
 466        <b><a href="postconf.5.html#smtpd_tls_mandatory_ciphers">smtpd_tls_mandatory_ciphers</a> (medium)</b>
 467               The  minimum TLS cipher grade that the Postfix SMTP
 468               server will use with mandatory TLS encryption.
 469
 470        <b><a href="postconf.5.html#smtpd_tls_mandatory_exclude_ciphers">smtpd_tls_mandatory_exclude_ciphers</a> (empty)</b>
 471               Additional list  of  ciphers  or  cipher  types  to
 472               exclude  from the SMTP server cipher list at manda-
 473               tory TLS security levels.
 474
 475        <b><a href="postconf.5.html#smtpd_tls_mandatory_protocols">smtpd_tls_mandatory_protocols</a> (SSLv3, TLSv1)</b>
 476               The SSL/TLS protocols accepted by the Postfix  SMTP
 477               server with mandatory TLS encryption.
 478
 479        <b><a href="postconf.5.html#smtpd_tls_received_header">smtpd_tls_received_header</a> (no)</b>
 480               Request  that  the  Postfix  SMTP  server  produces
 481               Received:  message headers that include information
 482               about  the protocol and cipher used, as well as the
 483               client CommonName  and  client  certificate  issuer
 484               CommonName.
 485
 486        <b><a href="postconf.5.html#smtpd_tls_req_ccert">smtpd_tls_req_ccert</a> (no)</b>
 487               With  mandatory  TLS  encryption, require a trusted
 488               remote SMTP client certificate in  order  to  allow
 489               TLS connections to proceed.
 490
 491        <b><a href="postconf.5.html#smtpd_tls_session_cache_database">smtpd_tls_session_cache_database</a> (empty)</b>
 492               Name  of  the  file containing the optional Postfix
 493               SMTP server TLS session cache.
 494
 495        <b><a href="postconf.5.html#smtpd_tls_session_cache_timeout">smtpd_tls_session_cache_timeout</a> (3600s)</b>
 496               The expiration time of Postfix SMTP server TLS ses-
 497               sion cache information.
 498
 499        <b><a href="postconf.5.html#smtpd_tls_wrappermode">smtpd_tls_wrappermode</a> (no)</b>
 500               Run  the  Postfix  SMTP  server in the non-standard
 501               "wrapper" mode, instead of using the STARTTLS  com-
 502               mand.
 503
 504        <b><a href="postconf.5.html#tls_daemon_random_bytes">tls_daemon_random_bytes</a> (32)</b>
 505               The  number  of pseudo-random bytes that an <a href="smtp.8.html"><b>smtp</b>(8)</a>
 506               or <a href="smtpd.8.html"><b>smtpd</b>(8)</a> process  requests  from  the  <a href="tlsmgr.8.html"><b>tlsmgr</b>(8)</a>
 507               server  in order to seed its internal pseudo random
 508               number generator (PRNG).
 509
 510        <b><a href="postconf.5.html#tls_high_cipherlist">tls_high_cipherlist</a></b>
 511        <b>(ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)</b>
 512               The OpenSSL cipherlist for "HIGH" grade ciphers.
 513
 514        <b><a href="postconf.5.html#tls_medium_cipherlist">tls_medium_cipherlist</a> (ALL:!EXPORT:!LOW:+RC4:@STRENGTH)</b>
 515               The OpenSSL cipherlist for "MEDIUM" or higher grade
 516               ciphers.
 517
 518        <b><a href="postconf.5.html#tls_low_cipherlist">tls_low_cipherlist</a> (ALL:!EXPORT:+RC4:@STRENGTH)</b>
 519               The  OpenSSL  cipherlist  for "LOW" or higher grade
 520               ciphers.
 521
 522        <b><a href="postconf.5.html#tls_export_cipherlist">tls_export_cipherlist</a> (ALL:+RC4:@STRENGTH)</b>
 523               The OpenSSL cipherlist for "EXPORT" or higher grade
 524               ciphers.
 525
 526        <b><a href="postconf.5.html#tls_null_cipherlist">tls_null_cipherlist</a> (eNULL:!aNULL)</b>
 527               The  OpenSSL  cipherlist  for  "NULL" grade ciphers
 528               that provide authentication without encryption.
 529
 530        Available in Postfix version 2.5 and later:
 531
 532        <b><a href="postconf.5.html#smtpd_tls_fingerprint_digest">smtpd_tls_fingerprint_digest</a> (md5)</b>
 533               The message  digest  algorithm  used  to  construct
 534               client-certificate         fingerprints         for
 535               <b><a href="postconf.5.html#check_ccert_access">check_ccert_access</a></b> and <b><a href="postconf.5.html#permit_tls_clientcerts">permit_tls_clientcerts</a></b>.
 536
 537        Available in Postfix version 2.6 and later:
 538
 539        <b><a href="postconf.5.html#smtpd_tls_protocols">smtpd_tls_protocols</a> (empty)</b>
 540               List of TLS protocols that the Postfix SMTP  server
 541               will  exclude  or  include  with  opportunistic TLS
 542               encryption.
 543
 544        <b><a href="postconf.5.html#smtpd_tls_ciphers">smtpd_tls_ciphers</a> (export)</b>
 545               The minimum TLS cipher grade that the Postfix  SMTP
 546               server  will use with opportunistic TLS encryption.
 547
 548        <b><a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a> (empty)</b>
 549               File with the Postfix SMTP server ECDSA certificate
 550               in PEM format.
 551
 552        <b><a href="postconf.5.html#smtpd_tls_eckey_file">smtpd_tls_eckey_file</a> ($<a href="postconf.5.html#smtpd_tls_eccert_file">smtpd_tls_eccert_file</a>)</b>
 553               File with the Postfix SMTP server ECDSA private key
 554               in PEM format.
 555
 556        <b><a href="postconf.5.html#smtpd_tls_eecdh_grade">smtpd_tls_eecdh_grade</a> (see 'postconf -d' output)</b>
 557               The  Postfix  SMTP  server   security   grade   for
 558               ephemeral elliptic-curve Diffie-Hellman (EECDH) key
 559               exchange.
 560
 561        <b><a href="postconf.5.html#tls_eecdh_strong_curve">tls_eecdh_strong_curve</a> (prime256v1)</b>
 562               The elliptic curve used by the SMTP server for sen-
 563               sibly strong ephemeral ECDH key exchange.
 564
 565        <b><a href="postconf.5.html#tls_eecdh_ultra_curve">tls_eecdh_ultra_curve</a> (secp384r1)</b>
 566               The elliptic curve used by the SMTP server for max-
 567               imally strong ephemeral ECDH key exchange.
 568
 569        Available in Postfix version 2.8 and later:
 570
 571        <b><a href="postconf.5.html#tls_preempts_cipherlist">tls_preempt_cipherlist</a> (no)</b>
 572               With SSLv3 and later, use the server's cipher pref-
 573               erence order instead of the client's cipher prefer-
 574               ence order.
 575
 576        <b><a href="postconf.5.html#tls_disable_workarounds">tls_disable_workarounds</a> (see 'postconf -d' output)</b>
 577               List or bit-mask of  OpenSSL  bug  work-arounds  to
 578               disable.
 579
 580 <b>OBSOLETE STARTTLS CONTROLS</b>
 581        The  following configuration parameters exist for compati-
 582        bility with Postfix versions before 2.3. Support for these
 583        will be removed in a future release.
 584
 585        <b><a href="postconf.5.html#smtpd_use_tls">smtpd_use_tls</a> (no)</b>
 586               Opportunistic  TLS:  announce  STARTTLS  support to
 587               SMTP clients, but do not require that  clients  use
 588               TLS encryption.
 589
 590        <b><a href="postconf.5.html#smtpd_enforce_tls">smtpd_enforce_tls</a> (no)</b>
 591               Mandatory  TLS:  announce  STARTTLS support to SMTP
 592               clients, and require that clients use  TLS  encryp-
 593               tion.
 594
 595        <b><a href="postconf.5.html#smtpd_tls_cipherlist">smtpd_tls_cipherlist</a> (empty)</b>
 596               Obsolete Postfix &lt; 2.3 control for the Postfix SMTP
 597               server TLS cipher list.
 598
 599 <b>VERP SUPPORT CONTROLS</b>
 600        With VERP style delivery,  each  recipient  of  a  message
 601        receives a customized copy of the message with his/her own
 602        recipient address encoded in the envelope sender  address.
 603        The <a href="VERP_README.html">VERP_README</a> file describes configuration and operation
 604        details of Postfix support for  variable  envelope  return
 605        path addresses.  VERP style delivery is requested with the
 606        SMTP XVERP command or with the "sendmail -V"  command-line
 607        option  and is available in Postfix version 1.1 and later.
 608
 609        <b><a href="postconf.5.html#default_verp_delimiters">default_verp_delimiters</a> (+=)</b>
 610               The two default VERP delimiter characters.
 611
 612        <b><a href="postconf.5.html#verp_delimiter_filter">verp_delimiter_filter</a> (-=+)</b>
 613               The characters Postfix accepts  as  VERP  delimiter
 614               characters  on the Postfix <a href="sendmail.1.html"><b>sendmail</b>(1)</a> command line
 615               and in SMTP commands.
 616
 617        Available in Postfix version 1.1 and 2.0:
 618
 619        <b><a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a> ($<a href="postconf.5.html#mynetworks">mynetworks</a>)</b>
 620               What SMTP clients are allowed to specify the  XVERP
 621               command.
 622
 623        Available in Postfix version 2.1 and later:
 624
 625        <b><a href="postconf.5.html#smtpd_authorized_verp_clients">smtpd_authorized_verp_clients</a> ($<a href="postconf.5.html#authorized_verp_clients">authorized_verp_clients</a>)</b>
 626               What  SMTP clients are allowed to specify the XVERP
 627               command.
 628
 629 <b>TROUBLE SHOOTING CONTROLS</b>
 630        The <a href="DEBUG_README.html">DEBUG_README</a> document describes how to debug parts  of
 631        the  Postfix mail system. The methods vary from making the
 632        software log a lot of detail, to running some daemon  pro-
 633        cesses under control of a call tracer or debugger.
 634
 635        <b><a href="postconf.5.html#debug_peer_level">debug_peer_level</a> (2)</b>
 636               The  increment  in  verbose  logging  level  when a
 637               remote client or server matches a  pattern  in  the
 638               <a href="postconf.5.html#debug_peer_list">debug_peer_list</a> parameter.
 639
 640        <b><a href="postconf.5.html#debug_peer_list">debug_peer_list</a> (empty)</b>
 641               Optional  list  of remote client or server hostname
 642               or network address patterns that cause the  verbose
 643               logging  level  to increase by the amount specified
 644               in $<a href="postconf.5.html#debug_peer_level">debug_peer_level</a>.
 645
 646        <b><a href="postconf.5.html#error_notice_recipient">error_notice_recipient</a> (postmaster)</b>
 647               The recipient  of  postmaster  notifications  about
 648               mail  delivery  problems that are caused by policy,
 649               resource, software or protocol errors.
 650
 651        <b><a href="postconf.5.html#internal_mail_filter_classes">internal_mail_filter_classes</a> (empty)</b>
 652               What categories of Postfix-generated mail are  sub-
 653               ject   to   before-queue   content   inspection  by
 654               <a href="postconf.5.html#non_smtpd_milters">non_smtpd_milters</a>, <a href="postconf.5.html#header_checks">header_checks</a> and <a href="postconf.5.html#body_checks">body_checks</a>.
 655
 656        <b><a href="postconf.5.html#notify_classes">notify_classes</a> (resource, software)</b>
 657               The list of error classes that are reported to  the
 658               postmaster.
 659
 660        <b><a href="postconf.5.html#smtpd_reject_footer">smtpd_reject_footer</a> (empty)</b>
 661               Optional  information  that  is appended after each
 662               SMTP server 4XX or 5XX response.
 663
 664        <b><a href="postconf.5.html#soft_bounce">soft_bounce</a> (no)</b>
 665               Safety net to keep mail queued that would otherwise
 666               be returned to the sender.
 667
 668        Available in Postfix version 2.1 and later:
 669
 670        <b><a href="postconf.5.html#smtpd_authorized_xclient_hosts">smtpd_authorized_xclient_hosts</a> (empty)</b>
 671               What  SMTP  clients  are allowed to use the XCLIENT
 672               feature.
 673
 674 <b>KNOWN VERSUS UNKNOWN RECIPIENT CONTROLS</b>
 675        As of Postfix version 2.0, the SMTP  server  rejects  mail
 676        for  unknown recipients. This prevents the mail queue from
 677        clogging up  with  undeliverable  MAILER-DAEMON  messages.
 678        Additional   information   on   this   topic   is  in  the
 679        <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a> and <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a> documents.
 680
 681        <b><a href="postconf.5.html#show_user_unknown_table_name">show_user_unknown_table_name</a> (yes)</b>
 682               Display  the  name  of  the  recipient table in the
 683               "User unknown" responses.
 684
 685        <b><a href="postconf.5.html#canonical_maps">canonical_maps</a> (empty)</b>
 686               Optional address mapping lookup tables for  message
 687               headers and envelopes.
 688
 689        <b><a href="postconf.5.html#recipient_canonical_maps">recipient_canonical_maps</a> (empty)</b>
 690               Optional address mapping lookup tables for envelope
 691               and header recipient addresses.
 692
 693        Parameters concerning known/unknown local recipients:
 694
 695        <b><a href="postconf.5.html#mydestination">mydestination</a>  ($<a href="postconf.5.html#myhostname">myhostname</a>,  localhost.$<a href="postconf.5.html#mydomain">mydomain</a>,  local-</b>
 696        <b>host)</b>
 697               The list of domains  that  are  delivered  via  the
 698               $<a href="postconf.5.html#local_transport">local_transport</a> mail delivery transport.
 699
 700        <b><a href="postconf.5.html#inet_interfaces">inet_interfaces</a> (all)</b>
 701               The network interface addresses that this mail sys-
 702               tem receives mail on.
 703
 704        <b><a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a> (empty)</b>
 705               The network interface addresses that this mail sys-
 706               tem  receives  mail on by way of a proxy or network
 707               address translation unit.
 708
 709        <b><a href="postconf.5.html#inet_protocols">inet_protocols</a> (ipv4)</b>
 710               The Internet protocols Postfix will attempt to  use
 711               when making or accepting connections.
 712
 713        <b><a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a>             (<a href="proxymap.8.html">proxy</a>:unix:passwd.byname</b>
 714        <b>$<a href="postconf.5.html#alias_maps">alias_maps</a>)</b>
 715               Lookup  tables with all names or addresses of local
 716               recipients: a recipient address is local  when  its
 717               domain  matches $<a href="postconf.5.html#mydestination">mydestination</a>, $<a href="postconf.5.html#inet_interfaces">inet_interfaces</a> or
 718               $<a href="postconf.5.html#proxy_interfaces">proxy_interfaces</a>.
 719
 720        <b><a href="postconf.5.html#unknown_local_recipient_reject_code">unknown_local_recipient_reject_code</a> (550)</b>
 721               The numerical Postfix  SMTP  server  response  code
 722               when    a   recipient   address   is   local,   and
 723               $<a href="postconf.5.html#local_recipient_maps">local_recipient_maps</a> specifies a  list  of  lookup
 724               tables that does not match the recipient.
 725
 726        Parameters  concerning  known/unknown  recipients of relay
 727        destinations:
 728
 729        <b><a href="postconf.5.html#relay_domains">relay_domains</a> ($<a href="postconf.5.html#mydestination">mydestination</a>)</b>
 730               What destination domains (and  subdomains  thereof)
 731               this system will relay mail to.
 732
 733        <b><a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> (empty)</b>
 734               Optional  lookup tables with all valid addresses in
 735               the domains that match $<a href="postconf.5.html#relay_domains">relay_domains</a>.
 736
 737        <b><a href="postconf.5.html#unknown_relay_recipient_reject_code">unknown_relay_recipient_reject_code</a> (550)</b>
 738               The numerical Postfix SMTP server reply code when a
 739               recipient   address   matches  $<a href="postconf.5.html#relay_domains">relay_domains</a>,  and
 740               <a href="postconf.5.html#relay_recipient_maps">relay_recipient_maps</a> specifies  a  list  of  lookup
 741               tables that does not match the recipient address.
 742
 743        Parameters  concerning known/unknown recipients in virtual
 744        alias domains:
 745
 746        <b><a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a> ($<a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a>)</b>
 747               Postfix is final destination for the specified list
 748               of  virtual  alias  domains,  that  is, domains for
 749               which all addresses are  aliased  to  addresses  in
 750               other local or remote domains.
 751
 752        <b><a href="postconf.5.html#virtual_alias_maps">virtual_alias_maps</a> ($<a href="postconf.5.html#virtual_maps">virtual_maps</a>)</b>
 753               Optional  lookup  tables  that  alias specific mail
 754               addresses or  domains  to  other  local  or  remote
 755               address.
 756
 757        <b><a href="postconf.5.html#unknown_virtual_alias_reject_code">unknown_virtual_alias_reject_code</a> (550)</b>
 758               The SMTP server reply code when a recipient address
 759               matches    $<a href="postconf.5.html#virtual_alias_domains">virtual_alias_domains</a>,    and     $<a href="postconf.5.html#virtual_alias_maps">vir</a>-
 760               <a href="postconf.5.html#virtual_alias_maps">tual_alias_maps</a>  specifies  a list of lookup tables
 761               that does not match the recipient address.
 762
 763        Parameters concerning known/unknown recipients in  virtual
 764        mailbox domains:
 765
 766        <b><a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a> ($<a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a>)</b>
 767               Postfix is final destination for the specified list
 768               of  domains;  mail  is  delivered  via  the   $<a href="postconf.5.html#virtual_transport">vir</a>-
 769               <a href="postconf.5.html#virtual_transport">tual_transport</a> mail delivery transport.
 770
 771        <b><a href="postconf.5.html#virtual_mailbox_maps">virtual_mailbox_maps</a> (empty)</b>
 772               Optional  lookup tables with all valid addresses in
 773               the domains that match $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>.
 774
 775        <b><a href="postconf.5.html#unknown_virtual_mailbox_reject_code">unknown_virtual_mailbox_reject_code</a> (550)</b>
 776               The SMTP server reply code when a recipient address
 777               matches    $<a href="postconf.5.html#virtual_mailbox_domains">virtual_mailbox_domains</a>,    and   $<a href="postconf.5.html#virtual_mailbox_maps">vir</a>-
 778               <a href="postconf.5.html#virtual_mailbox_maps">tual_mailbox_maps</a> specifies a list of lookup tables
 779               that does not match the recipient address.
 780
 781 <b>RESOURCE AND RATE CONTROLS</b>
 782        The  following parameters limit resource usage by the SMTP
 783        server and/or control client request rates.
 784
 785        <b><a href="postconf.5.html#line_length_limit">line_length_limit</a> (2048)</b>
 786               Upon input, long lines are chopped up  into  pieces
 787               of  at  most this length; upon delivery, long lines
 788               are reconstructed.
 789
 790        <b><a href="postconf.5.html#queue_minfree">queue_minfree</a> (0)</b>
 791               The minimal amount of free space in  bytes  in  the
 792               queue file system that is needed to receive mail.
 793
 794        <b><a href="postconf.5.html#message_size_limit">message_size_limit</a> (10240000)</b>
 795               The  maximal  size in bytes of a message, including
 796               envelope information.
 797
 798        <b><a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a> (1000)</b>
 799               The maximal number of recipients that  the  Postfix
 800               SMTP server accepts per message delivery request.
 801
 802        <b><a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a> (normal: 300s, overload: 10s)</b>
 803               The  time  limit  for sending a Postfix SMTP server
 804               response and for receiving  a  remote  SMTP  client
 805               request.
 806
 807        <b><a href="postconf.5.html#smtpd_history_flush_threshold">smtpd_history_flush_threshold</a> (100)</b>
 808               The  maximal  number  of  lines in the Postfix SMTP
 809               server command history before it  is  flushed  upon
 810               receipt of EHLO, RSET, or end of DATA.
 811
 812        Available in Postfix version 2.3 and later:
 813
 814        <b><a href="postconf.5.html#smtpd_peername_lookup">smtpd_peername_lookup</a> (yes)</b>
 815               Attempt to look up the remote SMTP client hostname,
 816               and verify that the  name  matches  the  client  IP
 817               address.
 818
 819        The per SMTP client connection count and request rate lim-
 820        its are implemented in co-operation with the <a href="anvil.8.html"><b>anvil</b>(8)</a> ser-
 821        vice,  and are available in Postfix version 2.2 and later.
 822
 823        <b><a href="postconf.5.html#smtpd_client_connection_count_limit">smtpd_client_connection_count_limit</a> (50)</b>
 824               How many simultaneous  connections  any  client  is
 825               allowed to make to this service.
 826
 827        <b><a href="postconf.5.html#smtpd_client_connection_rate_limit">smtpd_client_connection_rate_limit</a> (0)</b>
 828               The  maximal  number  of  connection  attempts  any
 829               client is allowed to make to this service per  time
 830               unit.
 831
 832        <b><a href="postconf.5.html#smtpd_client_message_rate_limit">smtpd_client_message_rate_limit</a> (0)</b>
 833               The  maximal  number  of  message delivery requests
 834               that any client is allowed to make to this  service
 835               per time unit, regardless of whether or not Postfix
 836               actually accepts those messages.
 837
 838        <b><a href="postconf.5.html#smtpd_client_recipient_rate_limit">smtpd_client_recipient_rate_limit</a> (0)</b>
 839               The maximal number of recipient addresses that  any
 840               client  is allowed to send to this service per time
 841               unit, regardless of whether or not Postfix actually
 842               accepts those recipients.
 843
 844        <b><a href="postconf.5.html#smtpd_client_event_limit_exceptions">smtpd_client_event_limit_exceptions</a> ($<a href="postconf.5.html#mynetworks">mynetworks</a>)</b>
 845               Clients       that      are      excluded      from
 846               smtpd_client_*_count/rate_limit restrictions.
 847
 848        Available in Postfix version 2.3 and later:
 849
 850        <b><a href="postconf.5.html#smtpd_client_new_tls_session_rate_limit">smtpd_client_new_tls_session_rate_limit</a> (0)</b>
 851               The maximal number of new (i.e., uncached) TLS ses-
 852               sions that a remote SMTP client is allowed to nego-
 853               tiate with this service per time unit.
 854
 855        Available in Postfix version 2.9 and later:
 856
 857        <b><a href="postconf.5.html#smtpd_per_record_deadline">smtpd_per_record_deadline</a> (normal: no, overload: yes)</b>
 858               Change  the  behavior  of  the  <a href="postconf.5.html#smtpd_timeout">smtpd_timeout</a>  time
 859               limit,  from  a time limit per read or write system
 860               call, to a time limit to send or receive a complete
 861               record  (an  SMTP command line, SMTP response line,
 862               SMTP message content line,  or  TLS  protocol  mes-
 863               sage).
 864
 865 <b>TARPIT CONTROLS</b>
 866        When  a  remote SMTP client makes errors, the Postfix SMTP
 867        server can insert delays before responding. This can  help
 868        to  slow  down  run-away  software.   The behavior is con-
 869        trolled by an error counter  that  counts  the  number  of
 870        errors  within an SMTP session that a client makes without
 871        delivering mail.
 872
 873        <b><a href="postconf.5.html#smtpd_error_sleep_time">smtpd_error_sleep_time</a> (1s)</b>
 874               With Postfix version 2.1 and later: the SMTP server
 875               response  delay  after  a client has made more than
 876               $<a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a>  errors,  and  fewer   than
 877               $<a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a>  errors, without delivering
 878               mail.
 879
 880        <b><a href="postconf.5.html#smtpd_soft_error_limit">smtpd_soft_error_limit</a> (10)</b>
 881               The number  of  errors  a  remote  SMTP  client  is
 882               allowed  to make without delivering mail before the
 883               Postfix SMTP server slows down all its responses.
 884
 885        <b><a href="postconf.5.html#smtpd_hard_error_limit">smtpd_hard_error_limit</a> (normal: 20, overload: 1)</b>
 886               The maximal number of errors a remote  SMTP  client
 887               is allowed to make without delivering mail.
 888
 889        <b><a href="postconf.5.html#smtpd_junk_command_limit">smtpd_junk_command_limit</a> (normal: 100, overload: 1)</b>
 890               The  number  of  junk commands (NOOP, VRFY, ETRN or
 891               RSET) that a remote SMTP client can send before the
 892               Postfix  SMTP  server starts to increment the error
 893               counter with each junk command.
 894
 895        Available in Postfix version 2.1 and later:
 896
 897        <b><a href="postconf.5.html#smtpd_recipient_overshoot_limit">smtpd_recipient_overshoot_limit</a> (1000)</b>
 898               The number of recipients that a remote SMTP  client
 899               can  send  in  excess  of  the limit specified with
 900               $<a href="postconf.5.html#smtpd_recipient_limit">smtpd_recipient_limit</a>,  before  the  Postfix  SMTP
 901               server  increments  the per-session error count for
 902               each excess recipient.
 903
 904 <b>ACCESS POLICY DELEGATION CONTROLS</b>
 905        As of version 2.1, Postfix can be configured  to  delegate
 906        access  policy  decisions  to an external server that runs
 907        outside Postfix.  See  the  file  <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a>  for
 908        more information.
 909
 910        <b><a href="postconf.5.html#smtpd_policy_service_max_idle">smtpd_policy_service_max_idle</a> (300s)</b>
 911               The  time  after which an idle SMTPD policy service
 912               connection is closed.
 913
 914        <b><a href="postconf.5.html#smtpd_policy_service_max_ttl">smtpd_policy_service_max_ttl</a> (1000s)</b>
 915               The time after which an active SMTPD policy service
 916               connection is closed.
 917
 918        <b><a href="postconf.5.html#smtpd_policy_service_timeout">smtpd_policy_service_timeout</a> (100s)</b>
 919               The  time  limit  for  connecting to, writing to or
 920               receiving from a delegated SMTPD policy server.
 921
 922 <b>ACCESS CONTROLS</b>
 923        The <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a> document gives an introduction  to
 924        all the SMTP server access control features.
 925
 926        <b><a href="postconf.5.html#smtpd_delay_reject">smtpd_delay_reject</a> (yes)</b>
 927               Wait  until  the  RCPT TO command before evaluating
 928               $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a>,    $smtpd_helo_restric-
 929               tions and $<a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a>, or wait until
 930               the     ETRN     command     before      evaluating
 931               $<a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> and $smtpd_helo_restric-
 932               tions.
 933
 934        <b><a href="postconf.5.html#parent_domain_matches_subdomains">parent_domain_matches_subdomains</a> (see 'postconf  -d'  out-</b>
 935        <b>put)</b>
 936               What   Postfix   features   match   subdomains   of
 937               "domain.tld" automatically, instead of requiring an
 938               explicit ".domain.tld" pattern.
 939
 940        <b><a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> (empty)</b>
 941               Optional SMTP server  access  restrictions  in  the
 942               context of a client SMTP connection request.
 943
 944        <b><a href="postconf.5.html#smtpd_helo_required">smtpd_helo_required</a> (no)</b>
 945               Require that a remote SMTP client introduces itself
 946               with the HELO or EHLO command  before  sending  the
 947               MAIL  command  or  other commands that require EHLO
 948               negotiation.
 949
 950        <b><a href="postconf.5.html#smtpd_helo_restrictions">smtpd_helo_restrictions</a> (empty)</b>
 951               Optional restrictions that the Postfix SMTP  server
 952               applies in the context of the SMTP HELO command.
 953
 954        <b><a href="postconf.5.html#smtpd_sender_restrictions">smtpd_sender_restrictions</a> (empty)</b>
 955               Optional  restrictions that the Postfix SMTP server
 956               applies in the context of the MAIL FROM command.
 957
 958        <b><a href="postconf.5.html#smtpd_recipient_restrictions">smtpd_recipient_restrictions</a>           (<a href="postconf.5.html#permit_mynetworks">permit_mynetworks</a>,</b>
 959        <b><a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a>)</b>
 960               The  access  restrictions  that  the  Postfix  SMTP
 961               server  applies  in the context of the RCPT TO com-
 962               mand.
 963
 964        <b><a href="postconf.5.html#smtpd_etrn_restrictions">smtpd_etrn_restrictions</a> (empty)</b>
 965               Optional SMTP server  access  restrictions  in  the
 966               context of a client ETRN request.
 967
 968        <b><a href="postconf.5.html#allow_untrusted_routing">allow_untrusted_routing</a> (no)</b>
 969               Forward    mail   with   sender-specified   routing
 970               (user[@%!]remote[@%!]site) from  untrusted  clients
 971               to destinations matching $<a href="postconf.5.html#relay_domains">relay_domains</a>.
 972
 973        <b><a href="postconf.5.html#smtpd_restriction_classes">smtpd_restriction_classes</a> (empty)</b>
 974               User-defined  aliases for groups of access restric-
 975               tions.
 976
 977        <b><a href="postconf.5.html#smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a> (</b>&lt;&gt;<b>)</b>
 978               The lookup key to be used in SMTP <a href="access.5.html"><b>access</b>(5)</a>  tables
 979               instead of the null sender address.
 980
 981        <b><a href="postconf.5.html#permit_mx_backup_networks">permit_mx_backup_networks</a> (empty)</b>
 982               Restrict  the  use  of  the  <a href="postconf.5.html#permit_mx_backup">permit_mx_backup</a>  SMTP
 983               access feature to only  domains  whose  primary  MX
 984               hosts match the listed networks.
 985
 986        Available in Postfix version 2.0 and later:
 987
 988        <b><a href="postconf.5.html#smtpd_data_restrictions">smtpd_data_restrictions</a> (empty)</b>
 989               Optional  access restrictions that the Postfix SMTP
 990               server applies in the context of the SMTP DATA com-
 991               mand.
 992
 993        <b><a href="postconf.5.html#smtpd_expansion_filter">smtpd_expansion_filter</a> (see 'postconf -d' output)</b>
 994               What  characters are allowed in $name expansions of
 995               RBL reply templates.
 996
 997        Available in Postfix version 2.1 and later:
 998
 999        <b><a href="postconf.5.html#smtpd_reject_unlisted_sender">smtpd_reject_unlisted_sender</a> (no)</b>
1000               Request that the Postfix SMTP server  rejects  mail
1001               from   unknown   sender  addresses,  even  when  no
1002               explicit <a href="postconf.5.html#reject_unlisted_sender">reject_unlisted_sender</a> access  restriction
1003               is specified.
1004
1005        <b><a href="postconf.5.html#smtpd_reject_unlisted_recipient">smtpd_reject_unlisted_recipient</a> (yes)</b>
1006               Request  that  the Postfix SMTP server rejects mail
1007               for  unknown  recipient  addresses,  even  when  no
1008               explicit  <a href="postconf.5.html#reject_unlisted_recipient">reject_unlisted_recipient</a> access restric-
1009               tion is specified.
1010
1011        Available in Postfix version 2.2 and later:
1012
1013        <b><a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a> (empty)</b>
1014               Optional access restrictions that the Postfix  SMTP
1015               server  applies  in the context of the SMTP END-OF-
1016               DATA command.
1017
1018 <b>SENDER AND RECIPIENT ADDRESS VERIFICATION CONTROLS</b>
1019        Postfix  version  2.1  introduces  sender  and   recipient
1020        address  verification.   This  feature  is  implemented by
1021        sending probe email messages that are not actually  deliv-
1022        ered.   This  feature  is requested via the reject_unveri-
1023        fied_sender   and    <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>    access
1024        restrictions.   The status of verification probes is main-
1025        tained by the <a href="verify.8.html"><b>verify</b>(8)</a> server.  See the file <a href="ADDRESS_VERIFICATION_README.html">ADDRESS_VER</a>-
1026        <a href="ADDRESS_VERIFICATION_README.html">IFICATION_README</a>  for  information  about how to configure
1027        and operate the Postfix sender/recipient address verifica-
1028        tion service.
1029
1030        <b><a href="postconf.5.html#address_verify_poll_count">address_verify_poll_count</a> (normal: 3, overload: 1)</b>
1031               How  many  times to query the <a href="verify.8.html"><b>verify</b>(8)</a> service for
1032               the completion of an address  verification  request
1033               in progress.
1034
1035        <b><a href="postconf.5.html#address_verify_poll_delay">address_verify_poll_delay</a> (3s)</b>
1036               The  delay between queries for the completion of an
1037               address verification request in progress.
1038
1039        <b><a href="postconf.5.html#address_verify_sender">address_verify_sender</a> ($<a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a>)</b>
1040               The sender address to use in  address  verification
1041               probes; prior to Postfix 2.5 the default was "post-
1042               master".
1043
1044        <b><a href="postconf.5.html#unverified_sender_reject_code">unverified_sender_reject_code</a> (450)</b>
1045               The numerical Postfix  SMTP  server  response  code
1046               when   a  recipient  address  is  rejected  by  the
1047               <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a> restriction.
1048
1049        <b><a href="postconf.5.html#unverified_recipient_reject_code">unverified_recipient_reject_code</a> (450)</b>
1050               The numerical Postfix SMTP server response  when  a
1051               recipient address is rejected by the reject_unveri-
1052               fied_recipient restriction.
1053
1054        Available in Postfix version 2.6 and later:
1055
1056        <b><a href="postconf.5.html#unverified_sender_defer_code">unverified_sender_defer_code</a> (450)</b>
1057               The numerical Postfix  SMTP  server  response  code
1058               when  a  sender address probe fails due to a tempo-
1059               rary error condition.
1060
1061        <b><a href="postconf.5.html#unverified_recipient_defer_code">unverified_recipient_defer_code</a> (450)</b>
1062               The numerical Postfix SMTP server response  when  a
1063               recipient  address  probe  fails due to a temporary
1064               error condition.
1065
1066        <b><a href="postconf.5.html#unverified_sender_reject_reason">unverified_sender_reject_reason</a> (empty)</b>
1067               The Postfix SMTP server's reply when rejecting mail
1068               with <a href="postconf.5.html#reject_unverified_sender">reject_unverified_sender</a>.
1069
1070        <b><a href="postconf.5.html#unverified_recipient_reject_reason">unverified_recipient_reject_reason</a> (empty)</b>
1071               The Postfix SMTP server's reply when rejecting mail
1072               with <a href="postconf.5.html#reject_unverified_recipient">reject_unverified_recipient</a>.
1073
1074        <b><a href="postconf.5.html#unverified_sender_tempfail_action">unverified_sender_tempfail_action</a>           ($<a href="postconf.5.html#reject_tempfail_action">reject_temp</a>-</b>
1075        <b><a href="postconf.5.html#reject_tempfail_action">fail_action</a>)</b>
1076               The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_sender">reject_unver</a>-
1077               <a href="postconf.5.html#reject_unverified_sender">ified_sender</a>  fails due to a temporary error condi-
1078               tion.
1079
1080        <b><a href="postconf.5.html#unverified_recipient_tempfail_action">unverified_recipient_tempfail_action</a>        ($<a href="postconf.5.html#reject_tempfail_action">reject_temp</a>-</b>
1081        <b><a href="postconf.5.html#reject_tempfail_action">fail_action</a>)</b>
1082               The Postfix SMTP server's action when <a href="postconf.5.html#reject_unverified_recipient">reject_unver</a>-
1083               <a href="postconf.5.html#reject_unverified_recipient">ified_recipient</a> fails due to a temporary error con-
1084               dition.
1085
1086 <b>ACCESS CONTROL RESPONSES</b>
1087        The following  parameters  control  numerical  SMTP  reply
1088        codes and/or text responses.
1089
1090        <b><a href="postconf.5.html#access_map_reject_code">access_map_reject_code</a> (554)</b>
1091               The numerical Postfix SMTP server response code for
1092               an <a href="access.5.html"><b>access</b>(5)</a> map "reject" action.
1093
1094        <b><a href="postconf.5.html#defer_code">defer_code</a> (450)</b>
1095               The numerical Postfix  SMTP  server  response  code
1096               when  a  remote  SMTP client request is rejected by
1097               the "defer" restriction.
1098
1099        <b><a href="postconf.5.html#invalid_hostname_reject_code">invalid_hostname_reject_code</a> (501)</b>
1100               The numerical Postfix  SMTP  server  response  code
1101               when  the  client HELO or EHLO command parameter is
1102               rejected   by   the    <a href="postconf.5.html#reject_invalid_helo_hostname">reject_invalid_helo_hostname</a>
1103               restriction.
1104
1105        <b><a href="postconf.5.html#maps_rbl_reject_code">maps_rbl_reject_code</a> (554)</b>
1106               The  numerical  Postfix  SMTP  server response code
1107               when a remote SMTP client request is blocked by the
1108               <a href="postconf.5.html#reject_rbl_client">reject_rbl_client</a>,             <a href="postconf.5.html#reject_rhsbl_client">reject_rhsbl_client</a>,
1109               <a href="postconf.5.html#reject_rhsbl_reverse_client">reject_rhsbl_reverse_client</a>, <a href="postconf.5.html#reject_rhsbl_sender">reject_rhsbl_sender</a> or
1110               <a href="postconf.5.html#reject_rhsbl_recipient">reject_rhsbl_recipient</a> restriction.
1111
1112        <b><a href="postconf.5.html#non_fqdn_reject_code">non_fqdn_reject_code</a> (504)</b>
1113               The numerical Postfix SMTP server reply code when a
1114               client    request    is     rejected     by     the
1115               <a href="postconf.5.html#reject_non_fqdn_helo_hostname">reject_non_fqdn_helo_hostname</a>,
1116               <a href="postconf.5.html#reject_non_fqdn_sender">reject_non_fqdn_sender</a> or <a href="postconf.5.html#reject_non_fqdn_recipient">reject_non_fqdn_recipient</a>
1117               restriction.
1118
1119        <b><a href="postconf.5.html#plaintext_reject_code">plaintext_reject_code</a> (450)</b>
1120               The  numerical  Postfix  SMTP  server response code
1121               when a request is  rejected  by  the  <b>reject_plain-</b>
1122               <b>text_session</b> restriction.
1123
1124        <b><a href="postconf.5.html#reject_code">reject_code</a> (554)</b>
1125               The  numerical  Postfix  SMTP  server response code
1126               when a remote SMTP client request  is  rejected  by
1127               the "reject" restriction.
1128
1129        <b><a href="postconf.5.html#relay_domains_reject_code">relay_domains_reject_code</a> (554)</b>
1130               The  numerical  Postfix  SMTP  server response code
1131               when  a  client  request   is   rejected   by   the
1132               <a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a> recipient restriction.
1133
1134        <b><a href="postconf.5.html#unknown_address_reject_code">unknown_address_reject_code</a> (450)</b>
1135               The  numerical  Postfix  SMTP  server response code
1136               when a sender or recipient address is  rejected  by
1137               the         <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>         or
1138               <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a> restriction.
1139
1140        <b><a href="postconf.5.html#unknown_client_reject_code">unknown_client_reject_code</a> (450)</b>
1141               The numerical Postfix  SMTP  server  response  code
1142               when  a  client without valid address &lt;=&gt; name map-
1143               ping is rejected by the reject_unknown_client_host-
1144               name restriction.
1145
1146        <b><a href="postconf.5.html#unknown_hostname_reject_code">unknown_hostname_reject_code</a> (450)</b>
1147               The  numerical  Postfix  SMTP  server response code
1148               when the hostname specified with the HELO  or  EHLO
1149               command        is       rejected       by       the
1150               <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> restriction.
1151
1152        Available in Postfix version 2.0 and later:
1153
1154        <b><a href="postconf.5.html#default_rbl_reply">default_rbl_reply</a> (see 'postconf -d' output)</b>
1155               The default SMTP server  response  template  for  a
1156               request  that  is rejected by an RBL-based restric-
1157               tion.
1158
1159        <b><a href="postconf.5.html#multi_recipient_bounce_reject_code">multi_recipient_bounce_reject_code</a> (550)</b>
1160               The numerical Postfix  SMTP  server  response  code
1161               when a remote SMTP client request is blocked by the
1162               <a href="postconf.5.html#reject_multi_recipient_bounce">reject_multi_recipient_bounce</a> restriction.
1163
1164        <b><a href="postconf.5.html#rbl_reply_maps">rbl_reply_maps</a> (empty)</b>
1165               Optional lookup tables with RBL response templates.
1166
1167        Available in Postfix version 2.6 and later:
1168
1169        <b><a href="postconf.5.html#access_map_defer_code">access_map_defer_code</a> (450)</b>
1170               The numerical Postfix SMTP server response code for
1171               an  <a href="access.5.html"><b>access</b>(5)</a>   map   "defer"   action,   including
1172               "<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>" or "<a href="postconf.5.html#defer_if_reject">defer_if_reject</a>".
1173
1174        <b><a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a> (<a href="postconf.5.html#defer_if_permit">defer_if_permit</a>)</b>
1175               The Postfix SMTP server's action when a reject-type
1176               restriction fails due to a temporary  error  condi-
1177               tion.
1178
1179        <b><a href="postconf.5.html#unknown_helo_hostname_tempfail_action">unknown_helo_hostname_tempfail_action</a>       ($<a href="postconf.5.html#reject_tempfail_action">reject_temp</a>-</b>
1180        <b><a href="postconf.5.html#reject_tempfail_action">fail_action</a>)</b>
1181               The    Postfix    SMTP    server's    action   when
1182               <a href="postconf.5.html#reject_unknown_helo_hostname">reject_unknown_helo_hostname</a> fails due to an tempo-
1183               rary error condition.
1184
1185        <b><a href="postconf.5.html#unknown_address_tempfail_action">unknown_address_tempfail_action</a> ($<a href="postconf.5.html#reject_tempfail_action">reject_tempfail_action</a>)</b>
1186               The    Postfix    SMTP    server's    action   when
1187               <a href="postconf.5.html#reject_unknown_sender_domain">reject_unknown_sender_domain</a>                     or
1188               <a href="postconf.5.html#reject_unknown_recipient_domain">reject_unknown_recipient_domain</a>  fail due to a tem-
1189               porary error condition.
1190
1191 <b>MISCELLANEOUS CONTROLS</b>
1192        <b><a href="postconf.5.html#config_directory">config_directory</a> (see 'postconf -d' output)</b>
1193               The default location of  the  Postfix  <a href="postconf.5.html">main.cf</a>  and
1194               <a href="master.5.html">master.cf</a> configuration files.
1195
1196        <b><a href="postconf.5.html#daemon_timeout">daemon_timeout</a> (18000s)</b>
1197               How  much time a Postfix daemon process may take to
1198               handle a request  before  it  is  terminated  by  a
1199               built-in watchdog timer.
1200
1201        <b><a href="postconf.5.html#command_directory">command_directory</a> (see 'postconf -d' output)</b>
1202               The  location  of  all  postfix administrative com-
1203               mands.
1204
1205        <b><a href="postconf.5.html#double_bounce_sender">double_bounce_sender</a> (double-bounce)</b>
1206               The sender address of postmaster notifications that
1207               are generated by the mail system.
1208
1209        <b><a href="postconf.5.html#ipc_timeout">ipc_timeout</a> (3600s)</b>
1210               The time limit for sending or receiving information
1211               over an internal communication channel.
1212
1213        <b><a href="postconf.5.html#mail_name">mail_name</a> (Postfix)</b>
1214               The mail system name that is displayed in Received:
1215               headers,  in  the  SMTP  greeting  banner,  and  in
1216               bounced mail.
1217
1218        <b><a href="postconf.5.html#mail_owner">mail_owner</a> (postfix)</b>
1219               The UNIX system account that owns the Postfix queue
1220               and most Postfix daemon processes.
1221
1222        <b><a href="postconf.5.html#max_idle">max_idle</a> (100s)</b>
1223               The  maximum  amount  of  time that an idle Postfix
1224               daemon process waits  for  an  incoming  connection
1225               before terminating voluntarily.
1226
1227        <b><a href="postconf.5.html#max_use">max_use</a> (100)</b>
1228               The  maximal  number of incoming connections that a
1229               Postfix daemon process will service  before  termi-
1230               nating voluntarily.
1231
1232        <b><a href="postconf.5.html#myhostname">myhostname</a> (see 'postconf -d' output)</b>
1233               The internet hostname of this mail system.
1234
1235        <b><a href="postconf.5.html#mynetworks">mynetworks</a> (see 'postconf -d' output)</b>
1236               The  list  of "trusted" SMTP clients that have more
1237               privileges than "strangers".
1238
1239        <b><a href="postconf.5.html#myorigin">myorigin</a> ($<a href="postconf.5.html#myhostname">myhostname</a>)</b>
1240               The domain name that locally-posted mail appears to
1241               come  from,  and that locally posted mail is deliv-
1242               ered to.
1243
1244        <b><a href="postconf.5.html#process_id">process_id</a> (read-only)</b>
1245               The process ID  of  a  Postfix  command  or  daemon
1246               process.
1247
1248        <b><a href="postconf.5.html#process_name">process_name</a> (read-only)</b>
1249               The  process  name  of  a Postfix command or daemon
1250               process.
1251
1252        <b><a href="postconf.5.html#queue_directory">queue_directory</a> (see 'postconf -d' output)</b>
1253               The location of the Postfix top-level queue  direc-
1254               tory.
1255
1256        <b><a href="postconf.5.html#recipient_delimiter">recipient_delimiter</a> (empty)</b>
1257               The separator between user names and address exten-
1258               sions (user+foo).
1259
1260        <b><a href="postconf.5.html#smtpd_banner">smtpd_banner</a> ($<a href="postconf.5.html#myhostname">myhostname</a> ESMTP $<a href="postconf.5.html#mail_name">mail_name</a>)</b>
1261               The text that follows the 220 status  code  in  the
1262               SMTP greeting banner.
1263
1264        <b><a href="postconf.5.html#syslog_facility">syslog_facility</a> (mail)</b>
1265               The syslog facility of Postfix logging.
1266
1267        <b><a href="postconf.5.html#syslog_name">syslog_name</a> (see 'postconf -d' output)</b>
1268               The  mail  system  name  that  is  prepended to the
1269               process name in syslog  records,  so  that  "smtpd"
1270               becomes, for example, "postfix/smtpd".
1271
1272        Available in Postfix version 2.2 and later:
1273
1274        <b><a href="postconf.5.html#smtpd_forbidden_commands">smtpd_forbidden_commands</a> (CONNECT, GET, POST)</b>
1275               List of commands that cause the Postfix SMTP server
1276               to immediately terminate the  session  with  a  221
1277               code.
1278
1279        Available in Postfix version 2.5 and later:
1280
1281        <b><a href="postconf.5.html#smtpd_client_port_logging">smtpd_client_port_logging</a> (no)</b>
1282               Enable  logging  of  the remote SMTP client port in
1283               addition to the hostname and IP address.
1284
1285 <b>SEE ALSO</b>
1286        <a href="anvil.8.html">anvil(8)</a>, connection/rate limiting
1287        <a href="cleanup.8.html">cleanup(8)</a>, message canonicalization
1288        <a href="tlsmgr.8.html">tlsmgr(8)</a>, TLS session and PRNG management
1289        <a href="trivial-rewrite.8.html">trivial-rewrite(8)</a>, address resolver
1290        <a href="verify.8.html">verify(8)</a>, address verification service
1291        <a href="postconf.5.html">postconf(5)</a>, configuration parameters
1292        <a href="master.5.html">master(5)</a>, generic daemon options
1293        <a href="master.8.html">master(8)</a>, process manager
1294        syslogd(8), system logging
1295
1296 <b>README FILES</b>
1297        <a href="ADDRESS_CLASS_README.html">ADDRESS_CLASS_README</a>, blocking unknown hosted or relay recipients
1298        <a href="ADDRESS_REWRITING_README.html">ADDRESS_REWRITING_README</a> Postfix address manipulation
1299        <a href="FILTER_README.html">FILTER_README</a>, external after-queue content filter
1300        <a href="LOCAL_RECIPIENT_README.html">LOCAL_RECIPIENT_README</a>, blocking unknown local recipients
1301        <a href="MILTER_README.html">MILTER_README</a>, before-queue mail filter applications
1302        <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, built-in access policies
1303        <a href="SMTPD_POLICY_README.html">SMTPD_POLICY_README</a>, external policy server
1304        <a href="SMTPD_PROXY_README.html">SMTPD_PROXY_README</a>, external before-queue content filter
1305        <a href="SASL_README.html">SASL_README</a>, Postfix SASL howto
1306        <a href="TLS_README.html">TLS_README</a>, Postfix STARTTLS howto
1307        <a href="VERP_README.html">VERP_README</a>, Postfix XVERP extension
1308        <a href="XCLIENT_README.html">XCLIENT_README</a>, Postfix XCLIENT extension
1309        <a href="XFORWARD_README.html">XFORWARD_README</a>, Postfix XFORWARD extension
1310
1311 <b>LICENSE</b>
1312        The  Secure  Mailer  license must be distributed with this
1313        software.
1314
1315 <b>AUTHOR(S)</b>
1316        Wietse Venema
1317        IBM T.J. Watson Research
1318        P.O. Box 704
1319        Yorktown Heights, NY 10598, USA
1320
1321        SASL support originally by:
1322        Till Franke
1323        SuSE Rhein/Main AG
1324        65760 Eschborn, Germany
1325
1326        TLS support originally by:
1327        Lutz Jaenicke
1328        BTU Cottbus
1329        Allgemeine Elektrotechnik
1330        Universitaetsplatz 3-4
1331        D-03044 Cottbus, Germany
1332
1333        Revised TLS support by:
1334        Victor Duchovni
1335        Morgan Stanley
1336
1337                                                                       SMTPD(8)
1338 </pre> </body> </html>