— aliases file for smtpd
This manual page describes the format of the aliases
used by smtpd(8)
. An alias in its simplest
form is used to assign an arbitrary name to an email address, or a group of
email addresses. This provides a convenient way to send mail. For example an
alias could refer to all users of a group: email to that alias would be sent
to all members of the group. Much more complex aliases can be defined however:
an alias can refer to other aliases, be used to send mail to a file instead of
another person, or to execute various commands.
Within the file, ‘
’ is a comment delimiter;
anything placed after it is discarded. The file consists of key/value mappings
of the form:
key: value1, value2, value3,
is always folded to lowercase before alias lookups to
ensure that there can be no ambiguity. The key is expanded to the
corresponding values, which consist of one or more of the following:
- A user on the host machine. The user must have a valid
entry in the passwd(5) database
- Append messages to file, specified by
its absolute pathname.
- Pipe the message to command on its
standard input. The command is run under the privileges of the daemon's
- Include any definitions in file as
alias entries. The format of the file is identical to this one.
- An email address in RFC 5322 format (see
mailaddr(7)). If an address extension
is appended to the user-part, it is first compared for an exact match. It
is then stripped so that an address such as firstname.lastname@example.org will only
use the part that precedes ‘+’ as a
- A status code and message to return. The code must be 3
digits, starting 4XX (TempFail) or 5XX (PermFail). The message must be
present and can be freely chosen.
- Deliver messages to Maildir at the
- Default aliases file.
file format appeared in