#++ # NAME # virtual 5 # SUMMARY # Postfix virtual alias table format # SYNOPSIS # \fBpostmap /etc/postfix/virtual\fR # # \fBpostmap -q "\fIstring\fB" /etc/postfix/virtual\fR # # \fBpostmap -q - /etc/postfix/virtual <\fIinputfile\fR # DESCRIPTION # The optional \fBvirtual\fR(5) alias table rewrites recipient # addresses for all local, all virtual, and all remote mail # destinations. # This is unlike the \fBaliases\fR(5) table which is used # only for \fBlocal\fR(8) delivery. Virtual aliasing is # recursive, and is implemented by the Postfix \fBcleanup\fR(8) # daemon before mail is queued. # # The main applications of virtual aliasing are: # .IP \(bu # To redirect mail for one address to one or more addresses. # .IP \(bu # To implement virtual alias domains where all addresses are aliased # to addresses in other domains. # .sp # Virtual alias domains are not to be confused with the virtual mailbox # domains that are implemented with the Postfix \fBvirtual\fR(8) mail # delivery agent. With virtual mailbox domains, each recipient address # can have its own mailbox. # .PP # Virtual aliasing is applied only to recipient # envelope addresses, and does not affect message headers. # Use \fBcanonical\fR(5) # mapping to rewrite header and envelope addresses in general. # # Normally, the \fBvirtual\fR(5) alias 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/virtual\fR" 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 case, the lookups # are done in a slightly different way as described below under # "REGULAR EXPRESSION TABLES" or "TCP-BASED TABLES". # CASE FOLDING # .ad # .fi # 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 regexp: or pcre: whose # lookup fields can match both upper and lower case. # TABLE FORMAT # .ad # .fi # The input format for the \fBpostmap\fR(1) command is as follows: # .IP "\fIpattern result\fR" # When \fIpattern\fR matches a mail address, replace it by the # corresponding \fIresult\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. # TABLE SEARCH ORDER # .ad # .fi # 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: # .IP "\fIuser\fR@\fIdomain address, address, ...\fR" # Redirect mail for \fIuser\fR@\fIdomain\fR to \fIaddress\fR. # This form has the highest precedence. # .IP "\fIuser address, address, ...\fR" # Redirect mail for \fIuser\fR@\fIsite\fR to \fIaddress\fR when # \fIsite\fR is equal to $\fBmyorigin\fR, when \fIsite\fR is listed in # $\fBmydestination\fR, or when it is listed in $\fBinet_interfaces\fR # or $\fBproxy_interfaces\fR. # .sp # This functionality overlaps with functionality of the local # \fIaliases\fR(5) database. The difference is that \fBvirtual\fR(5) # mapping can be applied to non-local addresses. # .IP "@\fIdomain address, address, ...\fR" # Redirect mail for other users in \fIdomain\fR to \fIaddress\fR. # This form has the lowest precedence. # .sp # Note: @\fIdomain\fR is a wild-card. With this form, the # Postfix SMTP server accepts # mail for any recipient in \fIdomain\fR, regardless of whether # that recipient exists. This may turn your mail system into # a backscatter source: Postfix first accepts mail for # non-existent recipients and then tries to return that mail # as "undeliverable" to the often forged sender address. # RESULT ADDRESS REWRITING # .ad # .fi # The lookup result is subject to address rewriting: # .IP \(bu # When the result has the form @\fIotherdomain\fR, the # result becomes the same \fIuser\fR in \fIotherdomain\fR. # This works only for the first address in a multi-address # lookup result. # .IP \(bu # When "\fBappend_at_myorigin=yes\fR", append "\fB@$myorigin\fR" # to addresses without "@domain". # .IP \(bu # When "\fBappend_dot_mydomain=yes\fR", append # "\fB.$mydomain\fR" to addresses without ".domain". # ADDRESS EXTENSION # .fi # .ad # 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, \fIuser+foo\fR, # \fIuser\fR, and @\fIdomain\fR. # # The \fBpropagate_unmatched_extensions\fR parameter controls whether # an unmatched address extension (\fI+foo\fR) is propagated to the # result of table lookup. # VIRTUAL ALIAS DOMAINS # .ad # .fi # Besides virtual aliases, the virtual alias table can also be used # to implement virtual alias domains. With a virtual alias domain, all # recipient addresses are aliased to addresses in other domains. # # Virtual alias domains are not to be confused with the virtual mailbox # domains that are implemented with the Postfix \fBvirtual\fR(8) mail # delivery agent. With virtual mailbox domains, each recipient address # can have its own mailbox. # # With a virtual alias domain, the virtual domain has its # own user name space. Local (i.e. non-virtual) usernames are not # visible in a virtual alias domain. In particular, local # \fBaliases\fR(5) and local mailing lists are not visible as # \fIlocalname@virtual-alias.domain\fR. # # Support for a virtual alias domain looks like: # # .nf # /etc/postfix/main.cf: # virtual_alias_maps = hash:/etc/postfix/virtual # .fi # # Note: some systems use \fBdbm\fR databases instead of \fBhash\fR. # See the output from "\fBpostconf -m\fR" for available database types. # # .nf # /etc/postfix/virtual: # \fIvirtual-alias.domain anything\fR (right-hand content does not matter) # \fIpostmaster@virtual-alias.domain postmaster\fR # \fIuser1@virtual-alias.domain address1\fR # \fIuser2@virtual-alias.domain address2, address3\fR # .fi # .sp # The \fIvirtual-alias.domain anything\fR entry is required for a # virtual alias domain. \fBWithout this entry, mail is rejected # with "relay access denied", or bounces with # "mail loops back to myself".\fR # # Do not specify virtual alias domain names in the \fBmain.cf # mydestination\fR or \fBrelay_domains\fR configuration parameters. # # With a virtual alias domain, the Postfix SMTP server # accepts mail for \fIknown-user@virtual-alias.domain\fR, and rejects # mail for \fIunknown-user\fR@\fIvirtual-alias.domain\fR as undeliverable. # # Instead of specifying the virtual alias domain name via # the \fBvirtual_alias_maps\fR table, you may also specify it via # the \fBmain.cf virtual_alias_domains\fR configuration parameter. # This latter parameter uses the same syntax as the \fBmain.cf # mydestination\fR configuration parameter. # REGULAR EXPRESSION TABLES # .ad # .fi # 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 # address being looked up. Thus, \fIuser@domain\fR mail addresses are not # broken up into their \fIuser\fR and \fI@domain\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. # # Results 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. # TCP-BASED TABLES # .ad # .fi # 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 \fBtcp_table\fR(5). # This feature is not available up to and including Postfix version 2.4. # # Each lookup operation uses the entire address once. Thus, # \fIuser@domain\fR mail addresses are not broken up into their # \fIuser\fR and \fI@domain\fR constituent parts, nor is # \fIuser+foo\fR broken up into \fIuser\fR and \fIfoo\fR. # # Results are the same as with indexed file lookups. # BUGS # The table format does not understand quoting conventions. # CONFIGURATION PARAMETERS # .ad # .fi # The following \fBmain.cf\fR parameters are especially relevant to # this topic. See the Postfix \fBmain.cf\fR file for syntax details # and for default values. Use the "\fBpostfix reload\fR" command after # a configuration change. # .IP \fBvirtual_alias_maps\fR # List of virtual aliasing tables. # .IP \fBvirtual_alias_domains\fR # List of virtual alias domains. This uses the same syntax # as the \fBmydestination\fR parameter. # .IP \fBpropagate_unmatched_extensions\fR # A list of address rewriting or forwarding mechanisms that propagate # an address extension from the original address to the result. # Specify zero or more of \fBcanonical\fR, \fBvirtual\fR, \fBalias\fR, # \fBforward\fR, \fBinclude\fR, or \fBgeneric\fR. # .PP # Other parameters of interest: # .IP \fBinet_interfaces\fR # The network interface addresses that this system receives mail on. # You need to stop and start Postfix when this parameter changes. # .IP \fBmydestination\fR # List of domains that this mail system considers local. # .IP \fBmyorigin\fR # The domain that is appended to any address that does not have a domain. # .IP \fBowner_request_special\fR # Give special treatment to \fBowner-\fIxxx\fR and \fIxxx\fB-request\fR # addresses. # .IP \fBproxy_interfaces\fR # Other interfaces that this machine receives mail on by way of a # proxy agent or network address translator. # SEE ALSO # cleanup(8), canonicalize and enqueue mail # postmap(1), Postfix lookup table manager # postconf(5), configuration parameters # canonical(5), canonical address mapping # README FILES # .ad # .fi # Use "\fBpostconf readme_directory\fR" or # "\fBpostconf html_directory\fR" to locate this information. # .na # .nf # ADDRESS_REWRITING_README, address rewriting guide # DATABASE_README, Postfix lookup table overview # VIRTUAL_README, domain hosting guide # LICENSE # .ad # .fi # The Secure Mailer license must be distributed with this software. # AUTHOR(S) # Wietse Venema # IBM T.J. Watson Research # P.O. Box 704 # Yorktown Heights, NY 10598, USA #--