NetBSD/gnu/dist/postfix/man/man5/access.5

.TH ACCESS 5 
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.SH NAME
access
\-
format of Postfix access table
.SH SYNOPSIS
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\fBpostmap /etc/postfix/access\fR
.SH DESCRIPTION
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The optional \fBaccess\fR table directs the Postfix SMTP server
to selectively reject or accept mail. Access can be allowed or
denied for specific host names, domain names, networks, host
network addresses or mail addresses.

Normally, the \fBaccess\fR table is specified as a text file
that serves as input to the \fBpostmap\fR(1) command.
The result, an indexed file in \fBdbm\fR or \fBdb\fR format,
is used for fast searching by the mail system. Execute the command
\fBpostmap /etc/postfix/access\fR in order to rebuild the indexed
file after changing the access table.

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. In that case,
the lookups are done in a slightly different way as described below.
.SH TABLE FORMAT
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The format of the access table is as follows:
.IP "\fIpattern action\fR"
When \fIpattern\fR matches a mail address, domain or host address,
perform the corresponding \fIaction\fR.
.IP "blank lines and comments"
Empty lines and whitespace-only lines are ignored, as
are lines whose first non-whitespace character is a `#'.
.IP "multi-line text"
A logical line starts with non-whitespace text. A line that
starts with whitespace continues a logical line.
.SH EMAIL ADDRESS PATTERNS
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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:
.IP \fIuser\fR@\fIdomain\fR
Matches the specified mail address.
.IP \fIdomain.tld\fR
Matches \fIdomain.tld\fR as the domain part of an email address.
.sp
The pattern \fIdomain.tld\fR also matches subdomains, but only
when the string \fBsmtpd_access_maps\fR is listed in the Postfix
\fBparent_domain_matches_subdomains\fR configuration setting.
Otherwise, specify \fI.domain.tld\fR (note the initial dot) in
order to match subdomains.
.IP \fIuser\fR@
Matches all mail addresses with the specified user part.
.PP
Note: lookup of the null sender address is not possible with
some types of lookup table. By default, Postfix uses \fB<>\fR
as the lookup key for such addresses. The value is specified with
the workaround is to specify \fBsmtpd_null_access_lookup_key\fR
parameter in the Postfix \fBmain.cf\fR file.
.SH ADDRESS EXTENSION
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When a mail address localpart contains the optional recipient delimiter
(e.g., \fIuser+foo\fR@\fIdomain\fR), the lookup order becomes:
\fIuser+foo\fR@\fIdomain\fR, \fIuser\fR@\fIdomain\fR, \fIdomain\fR,
\fIuser+foo\fR@, and \fIuser\fR@.
.SH HOST NAME/ADDRESS PATTERNS
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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:
.IP \fIdomain.tld\fR
Matches \fIdomain.tld\fR.
.sp
The pattern \fIdomain.tld\fR also matches subdomains, but only
when the string \fBsmtpd_access_maps\fR is listed in the Postfix
\fBparent_domain_matches_subdomains\fR configuration setting.
Otherwise, specify \fI.domain.tld\fR (note the initial dot) in
order to match subdomains.
.IP \fInet.work.addr.ess\fR
.IP \fInet.work.addr\fR
.IP \fInet.work\fR
.IP \fInet\fR
Matches any host address in the specified network. A network
address is a sequence of one or more octets separated by ".".
.SH ACTIONS
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.IP "[\fB45\fR]\fINN text\fR"
Reject the address etc. that matches the pattern, and respond with
the numerical code and text.
.IP \fBREJECT\fR
Reject the address etc. that matches the pattern. A generic
error response message is generated.
.IP \fBOK\fR
Accept the address etc. that matches the pattern.
.IP \fIall-numerical\fR
An all-numerical result is treated as OK. This format is
generated by address-based relay authorization schemes.
.IP \fIrestriction...\fR
Apply the named UCE restriction(s) (\fBpermit\fR, \fBreject\fR,
\fBreject_unauth_destination\fR, and so on).
.SH REGULAR EXPRESSION TABLES
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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 \fBregexp_table\fR(5)
or \fBpcre_table\fR(5).

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, \fIuser@domain\fR mail addresses are not broken up into
their \fIuser@\fR and \fIdomain\fR constituent parts, nor is
\fIuser+foo\fR broken up into \fIuser\fR and \fIfoo\fR.

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 interpolated as \fB$1\fR, \fB$2\fR and so on.
.SH BUGS
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The table format does not understand quoting conventions.
.SH SEE ALSO
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postmap(1) create mapping table
smtpd(8) smtp server
pcre_table(5) format of PCRE tables
regexp_table(5) format of POSIX regular expression tables
.SH LICENSE
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The Secure Mailer license must be distributed with this software.
.SH AUTHOR(S)
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Wietse Venema
IBM T.J. Watson Research
P.O. Box 704
Yorktown Heights, NY 10598, USA