I use aliases extensively, for administrative accounts (such as
abuse@, postmaster@, or webmaster@) or for expanding
givenname.surname@ to givenname@. I do so with ldap and, most
importantly, regexp databases because the latter enables me to
limit entering similar information multiple times.
For mailbox delivery, I use Dovecot. And Dovecot deals with
everything mailbox related such as quotas. For quotas it offers
a service that can be used as a milter by Postfix [1]. This works
great as long as mails are sent to real mailboxes and not to
aliases because Dovecot only knows about the real mailboxes and
not the aliases. In case a mail is sent to an alias, Dovecot
considers the mail being sent to a non-existent user, thus the
quota milter answers with a reject command.
One solution is to let Dovecot know about these aliases [2]. This
is quite easy for the ldap database, but it's not possible to
achieve for the regexp database because Dovecot doesn't support
this database type. Indeed, what I could do is transforming the
regexp database to ldap, but that would make administration more
difficult.
I know, it seems the issue arises because of a limitation on
Dovecot's side, but I have been wondering whether I can do
something on Postfix's side to solve it, namely:
Is it possible to expand aliases before contacting a milter?
If it was possible, I could solve the issue by only transmitting
"real" accounts to Dovecot. I haven't found any configuration
setting related to this. What I thought of was to write my own
milter that expands regexp tables and afterwards contacs
Dovecot's quota service, but this seems quite a tedious task.
I appreciate any ideas or hints.
Niklaas
1: http://wiki2.dovecot.org/Quota
2: http://marc.info/?l=dovecot&m=137536800105973&w=2
