table(5) — Linux manual page


TABLE(5)                 BSD File Formats Manual                TABLE(5)

NAME         top

     table — format description for smtpd tables

DESCRIPTION         top

     This manual page documents the file format for the various tables
     used in the smtpd(8) mail daemon.

     The format described here applies to tables as defined in

TABLE TYPES         top

     There are two types of tables: lists and mappings.  A list consists
     of a series of values, while a mapping consists of a series of keys
     and their associated values.  The following illustrates how to
     declare them as static tables:

           table mylist { value1, value2, value3 }
           table mymapping { key1 = value1, key2 = value2, key3 = value3 }

     When using a ‘file’ table, a list will be written with each value
     on a line by itself.  Comments can be put anywhere in the file
     using a hash mark (‘#’), and extend to the end of the current line.


     A mapping will be written with each key and value on a line,
     whitespaces separating both columns:

           key1    value1
           key2    value2
           key3    value3

     A file table can be converted to a Berkeley database using the
     makemap(8) utility with no syntax change.

     Tables using a ‘file’ or Berkeley DB backend will be referenced as

           table name file:/path/to/file
           table name db:/path/to/file.db

   Aliasing tables
     Aliasing tables are mappings that associate a recipient to one or
     many destinations.  They can be used in two contexts: primary
     domain aliases and virtual domain mapping.

           action name method alias <table>
           action name method virtual <table>

     In a primary domain context, the key is the user part of the
     recipient address, whilst the value is one or many recipients as
     described in aliases(5):

           user1   otheruser
           user2   otheruser1,otheruser2

     In a virtual domain context, the key is either a user part, a full
     email address or a catch-all, following selection rules described
     in smtpd.conf(5), and the value is one or many recipients as
     described in aliases(5):

           user1                   otheruser

     The following directive shares the same table format, but with a
     different meaning.  Here, the user is allowed to send mail from the
     listed addresses:

           listen on interface auth [...] senders <table>

   Domain tables
     Domain tables are simple lists of domains or hosts.

           match for domain <table> action name
           match helo <table> [...] action name

     In that context, the list of domains will be matched against the
     recipient domain or against the HELO name advertised by the sending
     host, respectively.  For ‘static’, ‘file’ and dbopen(3) backends, a
     wildcard may be used so the domain table may contain:


   Credentials tables
     Credentials tables are mappings of credentials.  They can be used
     in two contexts:

           listen on interface tls [...] auth <table>
           action name relay host relay-url auth <table>

     In a listener context, the credentials are a mapping of username
     and encrypted passwords:

           user1   $2b$10$hIJ4QfMcp.90nJwKqGbKM.MybArjHOTpEtoTV.DgLYAiThuoYmTSe
           user2   $2b$10$bwSmUOBGcZGamIfRuXGTvuTo3VLbPG9k5yeKNMBtULBhksV5KdGsK

     The passwords are to be encrypted using the smtpctl(8) encrypt

     In a relay context, the credentials are a mapping of labels and
     username:password pairs:

           label1  user:password

     The label must be unique and is used as a selector for the proper
     credentials when multiple credentials are valid for a single
     destination.  The password is not encrypted as it must be provided
     to the remote host.

   Netaddr tables
     Netaddr tables are lists of IPv4 and IPv6 network addresses.  They
     can only be used in the following context:

           match from src <table> action name

     When used as a "from source", the address of a client is compared
     to the list of addresses in the table until a match is found.

     A netaddr table can contain exact addresses or netmasks, and looks
     as follow:


   Userinfo tables
     Userinfo tables are used in rule context to specify an alternate
     userbase, mapping virtual users to local system users by UID, GID
     and home directory.

           action name method userbase <table>

     A userinfo table looks as follows:

           joe     1000:100:/home/virtual/joe
           jack    1000:100:/home/virtual/jack

     In this example, both joe and jack are virtual users mapped to the
     local system user with UID 1000 and GID 100, but different home
     directories.  These directories may contain a forward(5) file.
     This can be used in conjunction with an alias table that maps an
     email address or the domain part to the desired virtual username.
     For example:


   Source tables
     Source tables are lists of IPv4 and IPv6 addresses.  They can only
     be used in the following context:

           action name relay src <table>

     Successive queries to the source table will return the elements one
     by one.

     A source table looks as follow:


   Mailaddr tables
     Mailaddr tables are lists of email addresses.  They can be used in
     the following contexts:

           match mail-from <table> action name
           match rcpt-to <table> action name

     A mailaddr entry is used to match an email address against a
     username, a domain or a full email address.  A "*" wildcard may be
     used in part of the domain name.

     A mailaddr table looks as follow:


   Addrname tables
     Addrname tables are used to map IP addresses to hostnames.  They
     can be used in both listen context and relay context:

           listen on interface hostnames <table>
           action name relay helo-src <table>

     In listen context, the table is used to look up the server name to
     advertise depending on the local address of the socket on which a
     connection is accepted.  In relay context, the table is used to
     determine the hostname for the HELO sequence of the SMTP protocol,
     depending on the local address used for the outgoing connection.

     The format is a mapping from inet4 or inet6 addresses to hostnames:

           ::1             localhost

SEE ALSO         top

     smtpd.conf(5), makemap(8), smtpd(8)

COLOPHON         top

     This page is part of the OpenSMTPD (a FREE implementation of the
     server-side SMTP protocol) project.  Information about the project
     can be found at  If you have a bug
     report for this manual page, see
     ⟨⟩.  This page was
     obtained from the project's upstream Git repository
     ⟨⟩ on 2022-12-17.  (At
     that time, the date of the most recent commit that was found in the
     repository was 2022-09-30.)  If you discover any rendering problems
     in this HTML version of the page, or you believe there is a better
     or more up-to-date source for the page, or you have corrections or
     improvements to the information in this COLOPHON (which is not part
     of the original manual page), send a mail to

BSD                         February 13, 2021                        BSD