This documentation is for Dovecot v2.x, see wiki1 for v1.x documentation.

I wanted to use Dovecot to deal with mailboxes of non-unix users.

Assumptions

Making dovecot use these mailboxes

 auth = default
 auth_userdb = static uid=500 gid=500 home=/home/dovecot/users/%u
 auth_passdb = passwd-file /home/dovecot/passwd
 auth_user = dovecot

By the way, I did not bother making another set of configs to deal with non-virtual users - I use perdition for that in my migration scenario.

Making exim deliver to those virtual users

In order to make this work, exim must be able to read the /home/dovecot/users/ directory, otherwise delivery will not work.

Be carefull how you do this - test it with 'exim -bt <address>' for a few different options