virtual_user_post <filename>
virtual_user_pre <filename>
virtual_user_post: Adds a sendmail style virtual user table, actioned immediately before lookup.
virtual_user_pre: Adds a sendmail style virtual user table, actioned before any other local-user rules apply.
Both of these settings allow you to specify a file in which you provide aliases for user database names. In
sendmail this is the common way to add virtual domains.
We have added support for such a file to help with conversion to DMail. However we strongly recommend
that you move to our 'vdomain' style virtual domains so that you can take advantage of the features that
they offer now, and will offer in the future. We of course always continue to support these settings
so you do not have to change.
The difference between 'post' and 'pre' is when DSMTP looks up a user in these files. The 'pre' file
is used as soon as DSMTP gets a RCPT TO: line, before any other checks for mail redirection, including
the forward settings and alias files. Whereas the 'post' file is only checked just before the
user database lookup, after all other mail
redirection.
This means that if a message is addressed to bob and a lookup of the 'pre' file
results in that being an alias for the user, 1234, then DSMTP will forget about 'bob' and only look for
dmail.conf settings (including in alias files) for user '1234'. '1234' is also the username it will
lookup in the authentication module. Whereas if that same alias was in the 'post' file you could add
forward and alias settings for user 'bob' and still have his database 'username' of '1234'.
The pre and post files have the same syntax of one 'rule' per line of the form,
<source><tab><destination>
The following are example syntaxes, along with effective changes to recipient addresses for each one: