This file is indexed.

/usr/share/doc/postfix/html/access.5.html is in postfix-doc 2.11.0-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
<!doctype html public "-//W3C//DTD HTML 4.01 Transitional//EN"
        "http://www.w3.org/TR/html4/loose.dtd">
<html> <head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<title> Postfix manual - access(5) </title>
</head> <body> <pre>
ACCESS(5)                                                            ACCESS(5)

<b>NAME</b>
       access - Postfix SMTP server access table

<b>SYNOPSIS</b>
       <b>postmap /etc/postfix/access</b>

       <b>postmap -q "</b><i>string</i><b>" /etc/postfix/access</b>

       <b>postmap -q - /etc/postfix/access</b> &lt;<i>inputfile</i>

<b>DESCRIPTION</b>
       This  document  describes access control on remote SMTP client informa-
       tion: host names, network addresses, and envelope sender  or  recipient
       addresses;   it  is  implemented  by  the  Postfix  SMTP  server.   See
       <a href="header_checks.5.html"><b>header_checks</b>(5)</a> or <a href="header_checks.5.html"><b>body_checks</b>(5)</a> for access control on the content of
       email messages.

       Normally,  the  <a href="access.5.html"><b>access</b>(5)</a> table is specified as a text file that serves
       as input to the <a href="postmap.1.html"><b>postmap</b>(1)</a> command.  The result, an indexed file in <b>dbm</b>
       or  <b>db</b>  format,  is used for fast searching by the mail system. Execute
       the command "<b>postmap /etc/postfix/access</b>" to rebuild  an  indexed  file
       after changing the corresponding text file.

       When  the  table  is provided via other means such as NIS, LDAP or SQL,
       the same lookups are done as for ordinary indexed files.

       Alternatively, the table can be provided as  a  regular-expression  map
       where  patterns  are  given  as  regular expressions, or lookups can be
       directed to TCP-based server. In those cases, the lookups are done in a
       slightly  different  way  as  described below under "REGULAR EXPRESSION
       TABLES" or "TCP-BASED TABLES".

<b>CASE FOLDING</b>
       The search string is folded to lowercase before database lookup. As  of
       Postfix  2.3,  the search string is not case folded with database types
       such as <a href="regexp_table.5.html">regexp</a>: or <a href="pcre_table.5.html">pcre</a>: whose lookup fields can match both  upper  and
       lower case.

<b>TABLE FORMAT</b>
       The input format for the <a href="postmap.1.html"><b>postmap</b>(1)</a> command is as follows:

       <i>pattern action</i>
              When  <i>pattern</i>  matches  a  mail address, domain or host address,
              perform the corresponding <i>action</i>.

       blank lines and comments
              Empty lines and whitespace-only lines are ignored, as are  lines
              whose first non-whitespace character is a `#'.

       multi-line text
              A  logical  line  starts  with  non-whitespace text. A line that
              starts with whitespace continues a logical line.

<b>EMAIL ADDRESS PATTERNS</b>
       With lookups from indexed files such as DB or DBM,  or  from  networked
       tables  such  as  NIS,  LDAP or SQL, patterns are tried in the order as
       listed below:

       <i>user</i>@<i>domain</i>
              Matches the specified mail address.

       <i>domain.tld</i>
              Matches <i>domain.tld</i> as the domain part of an email address.

              The pattern <i>domain.tld</i> also matches subdomains,  but  only  when
              the  string  <b>smtpd_access_maps</b>  is  listed  in  the Postfix <b><a href="postconf.5.html#parent_domain_matches_subdomains">par</a>-</b>
              <b><a href="postconf.5.html#parent_domain_matches_subdomains">ent_domain_matches_subdomains</a></b> configuration setting.

       <i>.domain.tld</i>
              Matches subdomains of  <i>domain.tld</i>,  but  only  when  the  string
              <b>smtpd_access_maps</b>   is   not   listed   in   the   Postfix  <b><a href="postconf.5.html#parent_domain_matches_subdomains">par</a>-</b>
              <b><a href="postconf.5.html#parent_domain_matches_subdomains">ent_domain_matches_subdomains</a></b> configuration setting.

       <i>user</i>@  Matches all mail addresses with the specified user part.

       Note: lookup of the null sender address is not possible with some types
       of lookup table. By default, Postfix uses &lt;&gt; as the lookup key for such
       addresses. The value is specified with the <b><a href="postconf.5.html#smtpd_null_access_lookup_key">smtpd_null_access_lookup_key</a></b>
       parameter in the Postfix <a href="postconf.5.html"><b>main.cf</b></a> file.

<b>EMAIL ADDRESS EXTENSION</b>
       When a mail address localpart contains the optional recipient delimiter
       (e.g., <i>user+foo</i>@<i>domain</i>), the  lookup  order  becomes:  <i>user+foo</i>@<i>domain</i>,
       <i>user</i>@<i>domain</i>, <i>domain</i>, <i>user+foo</i>@, and <i>user</i>@.

<b>HOST NAME/ADDRESS PATTERNS</b>
       With  lookups  from  indexed files such as DB or DBM, or from networked
       tables such as NIS, LDAP or SQL,  the  following  lookup  patterns  are
       examined in the order as listed:

       <i>domain.tld</i>
              Matches <i>domain.tld</i>.

              The  pattern  <i>domain.tld</i>  also matches subdomains, but only when
              the string <b>smtpd_access_maps</b>  is  listed  in  the  Postfix  <b><a href="postconf.5.html#parent_domain_matches_subdomains">par</a>-</b>
              <b><a href="postconf.5.html#parent_domain_matches_subdomains">ent_domain_matches_subdomains</a></b> configuration setting.

       <i>.domain.tld</i>
              Matches  subdomains  of  <i>domain.tld</i>,  but  only  when the string
              <b>smtpd_access_maps</b>  is   not   listed   in   the   Postfix   <b><a href="postconf.5.html#parent_domain_matches_subdomains">par</a>-</b>
              <b><a href="postconf.5.html#parent_domain_matches_subdomains">ent_domain_matches_subdomains</a></b> configuration setting.

       <i>net.work.addr.ess</i>

       <i>net.work.addr</i>

       <i>net.work</i>

       <i>net</i>    Matches  the  specified IPv4 host address or subnetwork. An IPv4
              host address is a sequence of four decimal octets  separated  by
              ".".

              Subnetworks  are  matched  by  repeatedly  truncating  the  last
              ".octet" from the remote IPv4 host address string until a  match
              is found in the access table, or until further truncation is not
              possible.

              NOTE 1: The access map lookup key must be in canonical form:  do
              not specify unnecessary null characters, and do not enclose net-
              work address information with "[]" characters.

              NOTE 2: use the <b>cidr</b> lookup table type to  specify  network/net-
              mask patterns. See <a href="cidr_table.5.html"><b>cidr_table</b>(5)</a> for details.

       <i>net:work:addr:ess</i>

       <i>net:work:addr</i>

       <i>net:work</i>

       <i>net</i>    Matches  the  specified IPv6 host address or subnetwork. An IPv6
              host address is a sequence of three to eight  hexadecimal  octet
              pairs separated by ":".

              Subnetworks  are  matched  by  repeatedly  truncating  the  last
              ":octetpair" from the remote IPv6 host address  string  until  a
              match  is found in the access table, or until further truncation
              is not possible.

              NOTE 1: the truncation and comparison are done with  the  string
              representation  of  the IPv6 host address. Thus, not all the ":"
              subnetworks will be tried.

              NOTE 2: The access map lookup key must be in canonical form:  do
              not specify unnecessary null characters, and do not enclose net-
              work address information with "[]" characters.

              NOTE 3: use the <b>cidr</b> lookup table type to  specify  network/net-
              mask patterns. See <a href="cidr_table.5.html"><b>cidr_table</b>(5)</a> for details.

              IPv6 support is available in Postfix 2.2 and later.

<b>ACCEPT ACTIONS</b>
       <b>OK</b>     Accept the address etc. that matches the pattern.

       <i>all-numerical</i>
              An  all-numerical result is treated as OK. This format is gener-
              ated by address-based relay authorization schemes such  as  pop-
              before-smtp.

       For other accept actions, see "OTHER ACTIONS" below.

<b>REJECT ACTIONS</b>
       Postfix  version 2.3 and later support enhanced status codes as defined
       in <a href="http://tools.ietf.org/html/rfc3463">RFC 3463</a>.  When no code is specified at the beginning  of  the  <i>text</i>
       below, Postfix inserts a default enhanced status code of "5.7.1" in the
       case of reject actions, and "4.7.1" in the case of defer  actions.  See
       "ENHANCED STATUS CODES" below.

       <b>4</b><i>NN text</i>

       <b>5</b><i>NN text</i>
              Reject  the  address  etc. that matches the pattern, and respond
              with the numerical three-digit code and  text.  <b>4</b><i>NN</i>  means  "try
              again later", while <b>5</b><i>NN</i> means "do not try again".

              The  following  responses  have  special meaning for the Postfix
              SMTP server:

              <b>421</b> <i>text</i> (Postfix 2.3 and later)

              <b>521</b> <i>text</i> (Postfix 2.6 and later)
                     After responding with the numerical three-digit code  and
                     text,  disconnect immediately from the SMTP client.  This
                     frees up SMTP server resources so that they can  be  made
                     available to another SMTP client.

                     Note: The "521" response should be used only with botnets
                     and other malware where interoperability is  of  no  con-
                     cern.   The  "send  521  and  disconnect" behavior is NOT
                     defined in the SMTP standard.

       <b>REJECT</b> <i>optional text...</i>
              Reject the address etc. that matches  the  pattern.  Reply  with
              "<b>$<a href="postconf.5.html#access_map_reject_code">access_map_reject_code</a></b>  <i>optional  text...</i>"  when  the optional
              text is specified, otherwise reply with a generic error response
              message.

       <b>DEFER</b> <i>optional text...</i>
              Reject  the  address  etc.  that matches the pattern. Reply with
              "<b>$<a href="postconf.5.html#access_map_defer_code">access_map_defer_code</a></b> <i>optional text...</i>" when the optional text
              is specified, otherwise reply with a generic error response mes-
              sage.

              This feature is available in Postfix 2.6 and later.

       <b>DEFER_IF_REJECT</b> <i>optional text...</i>
              Defer the request if some later restriction would  result  in  a
              REJECT action. Reply with "<b>$<a href="postconf.5.html#access_map_defer_code">access_map_defer_code</a> 4.7.1</b> <i>optional</i>
              <i>text...</i>" when the optional text is  specified,  otherwise  reply
              with a generic error response message.

              Prior to Postfix 2.6, the SMTP reply code is 450.

              This feature is available in Postfix 2.1 and later.

       <b>DEFER_IF_PERMIT</b> <i>optional text...</i>
              Defer the request if some later restriction would result in a an
              explicit   or    implicit    PERMIT    action.     Reply    with
              "<b>$<a href="postconf.5.html#access_map_defer_code">access_map_defer_code</a>   4.7.1</b>    <i>optional  text...</i>"  when  the
              optional text is specified, otherwise reply with a generic error
              response message.

              Prior to Postfix 2.6, the SMTP reply code is 450.

              This feature is available in Postfix 2.1 and later.

       For other reject actions, see "OTHER ACTIONS" below.

<b>OTHER ACTIONS</b>
       <i>restriction...</i>
              Apply    the   named   UCE   restriction(s)   (<b>permit</b>,   <b>reject</b>,
              <b><a href="postconf.5.html#reject_unauth_destination">reject_unauth_destination</a></b>, and so on).

       <b>BCC</b> <i>user@domain</i>
              Send one copy of the message to the specified recipient.

              If multiple BCC actions are specified within the same SMTP  MAIL
              transaction, only the last action will be used.

              This feature is not part of the stable Postfix release.

       <b>DISCARD</b> <i>optional text...</i>
              Claim successful delivery and silently discard the message.  Log
              the optional text if specified, otherwise log a generic message.

              Note:  this  action currently affects all recipients of the mes-
              sage.  To discard only  one  recipient  without  discarding  the
              entire message, use the <a href="transport.5.html">transport(5)</a> table to direct mail to the
              <a href="discard.8.html">discard(8)</a> service.

              This feature is available in Postfix 2.0 and later.

       <b>DUNNO</b>  Pretend that the lookup key was not found. This prevents Postfix
              from  trying  substrings  of the lookup key (such as a subdomain
              name, or a network address subnetwork).

              This feature is available in Postfix 2.0 and later.

       <b>FILTER</b> <i>transport:destination</i>
              After the message is queued, send the entire message through the
              specified  external content filter. The <i>transport</i> name specifies
              the first field of a mail  delivery  agent  definition  in  <a href="master.5.html">mas-
              ter.cf</a>;  the  syntax of the next-hop <i>destination</i> is described in
              the manual page  of  the  corresponding  delivery  agent.   More
              information  about  external  content  filters is in the Postfix
              <a href="FILTER_README.html">FILTER_README</a> file.

              Note 1: do not use $<i>number</i> regular expression substitutions  for
              <i>transport</i>  or  <i>destination</i>  unless you know that the information
              has a trusted origin.

              Note 2: this action overrides the  <a href="postconf.5.html">main.cf</a>  <b><a href="postconf.5.html#content_filter">content_filter</a></b>  set-
              ting,  and  affects  all  recipients of the message. In the case
              that multiple <b>FILTER</b> actions fire, only the  last  one  is  exe-
              cuted.

              Note 3: the purpose of the FILTER command is to override message
              routing.  To override the  recipient's  <i>transport</i>  but  not  the
              next-hop <i>destination</i>, specify an empty filter <i>destination</i> (Post-
              fix 2.7 and later),  or  specify  a  <i>transport:destination</i>  that
              delivers  through  a different Postfix instance (Postfix 2.6 and
              earlier). Other options are using the recipient-dependent <b><a href="postconf.5.html#transport_maps">trans</a>-</b>
              <b><a href="postconf.5.html#transport_maps">port_maps</a></b>   or  the  sender-dependent  <b><a href="postconf.5.html#sender_dependent_default_transport_maps">sender_dependent_default-</b>
              <b>_transport_maps</a></b> features.

              This feature is available in Postfix 2.0 and later.

       <b>HOLD</b> <i>optional text...</i>
              Place the message on the <b>hold</b> queue, where  it  will  sit  until
              someone  either deletes it or releases it for delivery.  Log the
              optional text if specified, otherwise log a generic message.

              Mail that is placed on hold can be examined with the  <a href="postcat.1.html"><b>postcat</b>(1)</a>
              command,  and can be destroyed or released with the <a href="postsuper.1.html"><b>postsuper</b>(1)</a>
              command.

              Note: use "<b>postsuper -r</b>" to release mail that was kept  on  hold
              for   a   significant  fraction  of  <b>$<a href="postconf.5.html#maximal_queue_lifetime">maximal_queue_lifetime</a></b>  or
              <b>$<a href="postconf.5.html#bounce_queue_lifetime">bounce_queue_lifetime</a></b>, or longer. Use "<b>postsuper -H</b>"  only  for
              mail that will not expire within a few delivery attempts.

              Note:  this  action currently affects all recipients of the mes-
              sage.

              This feature is available in Postfix 2.0 and later.

       <b>PREPEND</b> <i>headername: headervalue</i>
              Prepend the specified message header to the message.  When  more
              than  one  PREPEND  action  executes, the first prepended header
              appears before the second etc. prepended header.

              Note: this action must execute before  the  message  content  is
              received;    it    cannot    execute    in    the   context   of
              <b><a href="postconf.5.html#smtpd_end_of_data_restrictions">smtpd_end_of_data_restrictions</a></b>.

              This feature is available in Postfix 2.1 and later.

       <b>REDIRECT</b> <i>user@domain</i>
              After the message is queued, send the message to  the  specified
              address instead of the intended recipient(s).

              Note:  this  action  overrides  the FILTER action, and currently
              affects all recipients of the message.

              This feature is available in Postfix 2.1 and later.

       <b>WARN</b> <i>optional text...</i>
              Log a warning with  the  optional  text,  together  with  client
              information  and  if available, with helo, sender, recipient and
              protocol information.

              This feature is available in Postfix 2.1 and later.

<b>ENHANCED STATUS CODES</b>
       Postfix version 2.3 and later support enhanced status codes as  defined
       in  <a href="http://tools.ietf.org/html/rfc3463">RFC  3463</a>.   When an enhanced status code is specified in an access
       table, it is subject to modification. The following transformations are
       needed  when the same access table is used for client, helo, sender, or
       recipient access restrictions; they happen regardless of whether  Post-
       fix replies to a MAIL FROM, RCPT TO or other SMTP command.

       <b>o</b>      When  a sender address matches a REJECT action, the Postfix SMTP
              server will transform a recipient DSN status (e.g., 4.1.1-4.1.6)
              into the corresponding sender DSN status, and vice versa.

       <b>o</b>      When  non-address  information  matches a REJECT action (such as
              the HELO command argument or the client  hostname/address),  the
              Postfix  SMTP  server  will  transform a sender or recipient DSN
              status into a generic non-address DSN status (e.g., 4.0.0).

<b>REGULAR EXPRESSION TABLES</b>
       This section describes how the table lookups change when the  table  is
       given  in the form of regular expressions. For a description of regular
       expression lookup table syntax, see <a href="regexp_table.5.html"><b>regexp_table</b>(5)</a> or <a href="pcre_table.5.html"><b>pcre_table</b>(5)</a>.

       Each pattern is a regular expression that  is  applied  to  the  entire
       string being looked up. Depending on the application, that string is an
       entire client hostname, an entire client IP address, or an entire  mail
       address.  Thus,  no  parent  domain  or  parent network search is done,
       <i>user@domain</i> mail addresses are not  broken  up  into  their  <i>user@</i>  and
       <i>domain</i>  constituent parts, nor is <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.

       Patterns are applied in the order as specified in the  table,  until  a
       pattern is found that matches the search string.

       Actions  are the same as with indexed file lookups, with the additional
       feature that parenthesized substrings from the pattern can be  interpo-
       lated as <b>$1</b>, <b>$2</b> and so on.

<b>TCP-BASED TABLES</b>
       This  section  describes  how the table lookups change when lookups are
       directed  to  a  TCP-based  server.  For  a  description  of  the   TCP
       client/server  lookup  protocol, see <a href="tcp_table.5.html"><b>tcp_table</b>(5)</a>.  This feature is not
       available up to and including Postfix version 2.4.

       Each lookup operation uses the entire query string once.  Depending  on
       the  application,  that  string is an entire client hostname, an entire
       client IP address, or an entire mail address.  Thus, no  parent  domain
       or  parent  network  search is done, <i>user@domain</i> mail addresses are not
       broken up into  their  <i>user@</i>  and  <i>domain</i>  constituent  parts,  nor  is
       <i>user+foo</i> broken up into <i>user</i> and <i>foo</i>.

       Actions are the same as with indexed file lookups.

<b>EXAMPLE</b>
       The  following example uses an indexed file, so that the order of table
       entries does not matter. The example permits access by  the  client  at
       address 1.2.3.4 but rejects all other clients in 1.2.3.0/24. Instead of
       <b>hash</b> lookup tables, some systems use <b>dbm</b>.  Use  the  command  "<b>postconf</b>
       <b>-m</b>" to find out what lookup tables Postfix supports on your system.

       /etc/postfix/<a href="postconf.5.html">main.cf</a>:
           <a href="postconf.5.html#smtpd_client_restrictions">smtpd_client_restrictions</a> =
               <a href="postconf.5.html#check_client_access">check_client_access</a> <a href="DATABASE_README.html#types">hash</a>:/etc/postfix/access

       /etc/postfix/access:
           1.2.3   REJECT
           1.2.3.4 OK

       Execute  the  command  "<b>postmap  /etc/postfix/access</b>" after editing the
       file.

<b>BUGS</b>
       The table format does not understand quoting conventions.

<b>SEE ALSO</b>
       <a href="postmap.1.html">postmap(1)</a>, Postfix lookup table manager
       <a href="smtpd.8.html">smtpd(8)</a>, SMTP server
       <a href="postconf.5.html">postconf(5)</a>, configuration parameters
       <a href="transport.5.html">transport(5)</a>, transport:nexthop syntax

<b>README FILES</b>
       <a href="SMTPD_ACCESS_README.html">SMTPD_ACCESS_README</a>, built-in SMTP server access control
       <a href="DATABASE_README.html">DATABASE_README</a>, Postfix lookup table overview

<b>LICENSE</b>
       The Secure Mailer license must be distributed with this software.

<b>AUTHOR(S)</b>
       Wietse Venema
       IBM T.J. Watson Research
       P.O. Box 704
       Yorktown Heights, NY 10598, USA

                                                                     ACCESS(5)
</pre> </body> </html>