table(5) — Linux manual page

NAME | DESCRIPTION | TABLE TYPES | SEE ALSO | COLOPHON

TABLE(5)                   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
       smtpd.conf(5).

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.

             value1
             value2
             value3

       A mapping will be written with each key and value on a line,
       whitespace and an optional colon separating both columns:

             key1:   value1
             key2    value2
             key3    value3

       Blank lines, leading and trailing spaces and tabs are ignored.
       Lines whose first non-space character is a hash mark (‘#’) are
       comments and are ignored.  To force the parsing of a file table
       as a list rather than a mapping, use this special comment:

             # @list

       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 follows:

             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
             user3   [email protected]

       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
             [email protected]       otheruser1,otheruser2
             @example.org            [email protected]
             @                       [email protected]

       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:

             example.org
             *.example.org

   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
       subcommand.

       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:

             192.168.1.1
             [::1]
             192.168.1.0/24

       IPv6 addresses must be enclosed in square brackets.

   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:

             [email protected]     joe
             [email protected]    jack

   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:

             192.168.1.2
             192.168.1.3
             [::1]
             [::2]

       IPv6 address must be enclosed in square brackets.

   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:

             user
             @domain
             user@domain
             user@*.domain

   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
             127.0.0.1       localhost
             88.190.23.165   www.opensmtpd.org

       IPv6 addresses must be enclosed in square brackets.

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 https://www.opensmtpd.org/.  If you have
       a bug report for this manual page, see
       ⟨https://github.com/OpenSMTPD/OpenSMTPD/issues⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨https://github.com/OpenSMTPD/OpenSMTPD.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2024-06-09.)  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
       [email protected]

GNU                            May 2, 2024                      TABLE(5)