Username aliases

[Eirik Rye]

Hi,

Our organization is currently using a passwd-file user database for our 
Dovecot installs. However, we now want to provide simple username aliases.

We currently use usernames that are -not- equal to the email address, 
but due to the fact that many major email clients/providers do not even 
allow you to specifiy a username, we now want to provide aliases where 
the username is equal to the email address.

A simple solution would be to duplicate the lines in the passwd-file, 
with the email address as the username, but this does not seem be ideal 
due to data duplication.

Ideally, there would be a secondary 'alias' userdb, which on a match 
would then restart the search in the primary passwd-file userdb using 
the new username. Is this possible?

What would be the best way to go about this?