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

makemapcreate database maps for smtpd

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

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 character.

The options are as follows:

dbtype
Specify the format of the database. Available formats are hash and btree. The default value is hash.
dbfile
Write the generated database to dbfile.
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:
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.
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.
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 example:

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@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"

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

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

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

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

February 13, 2021 OpenBSD-current