[Dovecot] Dovecot Virtual Users & Sendmail

Not directly Dovecot, but a configuration problem.

We have a working set-up with Dovecot+Procmail+Sendmail, using POP-before-SMTP. We want to be able to offer email accounts to some local schools, using SquirrelMail (keeps their costs & maintenance down). The whole arrangement is working, but we don't want to have to have 300+ School children as users of our Red Hat Enterprise server, so I've set up a passwd style file for authentication.

This all works fine, they can access mailboxes & send emails, but to receive Sendmail is checking that they are unix users & bounces messages back if they aren't in /etc/passwd too.

Has anybody ever got Sendmail working with Dovecot virtual users?

Or is it time I switched to Postfix?

Chris Hogan