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. makemap itself creates the database maps used by keyed map
lookups specified in smtpd.conf(5).
makemap 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, makemap 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:
Specify the format of the database. Available formats are
hash and btree. The default value is hash.
Write the generated database to dbfile.
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 maps.
-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
“firstname.lastname@example.org” 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 “email@example.com user” to
the users map. To handle all mail destined to any user at
example.com, add “@example.com 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 "example.org" action "local"
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 2023-06-23. (At
that time, the date of the most recent commit that was found in the
repository was 2023-06-23.) 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 firstname.lastname@example.org
BSD February 13, 2021 BSD