makemap(8) — Linux manual page


MAKEMAP(8)               System Manager's Manual              MAKEMAP(8)

NAME         top

       makemap — create database maps for smtpd

SYNOPSIS         top

       makemap [-U] [-d dbtype] [-o dbfile] [-t type] file

DESCRIPTION         top

       Maps provide a generic interface for associating a textual key to
       a value.  Such associations may be accessed through a plaintext
       file, database, or DNS.  The format of these file types is
       described below.  itself creates the database maps used by keyed
       map lookups specified in smtpd.conf(5).

       reads input from file and writes data to a file which is named by
       adding a “.db” suffix to file.  The current line can be extended
       over multiple lines using a backslash (‘\’).  Comments can be put
       anywhere in the file using a hash mark (‘#’), and extend to the
       end of the current line.  Care should be taken when commenting
       out multi-line text: the comment is effective until the end of
       the entire block.  In all cases, reads lines consisting of words
       separated by whitespace.  The first word of a line is the
       database key; the remainder represents the mapped value.  The
       database key and value may optionally be separated by the colon

       The options are as follows:

       -d dbtype
               Specify the format of the database.  Available formats
               are hash and btree.  The default value is hash.

       -o dbfile
               Write the generated database to dbfile.

       -t type
               Specify the format of the resulting map file.  The
               default map format is suitable for storing simple,
               unstructured, key-to-value string associations.  However,
               if the mapped value has special meaning, as in the case
               of a virtual domains file, a suitable type must be
               provided.  The available output types are:

               aliases  The mapped value is a comma-separated list of
                        mail destinations.  This format can be used for
                        building user aliases and user mappings for
                        virtual domain files.

               set      There is no mapped value – a map of this type
                        will only allow for the lookup of keys.  This
                        format can be used for building primary domain

       -U      Instead of generating a database map from text input,
               dump the contents of a database map as text with the key
               and value separated with a tab.


       Primary domains can be kept in tables.  To create a primary
       domain table, add each primary domain on a single line by itself.

       In addition to adding an entry to the primary domain map, one
       must add a filter rule that accepts mail for the domain map, for

             table domains db:/etc/mail/domains.db

             action "local" mbox

             match for domain <domains> action "local"


       Virtual domains may also be kept in tables.  To create a virtual
       domain table, add each virtual domain on a single line by itself.

       Virtual domains expect a mapping of virtual users to real users
       in order to determine if a recipient is accepted or not.  The
       mapping format is an extension to aliases(5), which allows the
       use of “user@domain.tld” to accept user only on the specified
       domain, “user” to accept the user for any of the virtual domains,
       “@domain.tld” to provide a catch-all for the specified domain and
       “@” to provide a global catch-all for all domains.  smtpd(8) will
       perform the lookups in that specific order.

       To create a single virtual address, add “ user”
       to the users map.  To handle all mail destined to any user at, add “ user” to the virtual map.

       In addition to adding an entry to the virtual map, one must add a
       filter rule that accepts mail for virtual domains, for example:

             table vdomains db:/etc/mail/vdomains.db
             table vusers db:/etc/mail/users.db

             action "local" mbox virtual <vusers>

             match for domain <vdomains> action "local"
             match for domain "" action "local"

FILES         top

       /etc/mail/aliases     List of user mail aliases.
       /etc/mail/secrets     List of remote host credentials.

EXIT STATUS         top

       The makemap utility exits 0 on success, and >0 if an error

SEE ALSO         top

       aliases(5), smtpd.conf(5), table(5), newaliases(8), smtpd(8)

HISTORY         top

       The command first appeared in OpenBSD 4.6 as a replacement for
       the equivalent command shipped with sendmail.

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 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-12-05.)  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
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       (which is not part of the original manual page), send a mail to

GNU                         February 13, 2021                 MAKEMAP(8)