Hi Chris,

We migrated to Dovecot from Qpopper/UW-IMAP in July. We previously looked at altering the Dovecot code, client-side duplicate email cleanup utilities (for Eudora), and enforcing "download-then-delete from the server" prior to the migration.

We got around the "downloading of previously downloaded emails" problem by moving all previously downloaded emails to a new folder called "ConvertedMail" during the conversion process from mbox (Qpopper) to maildir. This assumes you're going to maildir though. The benefit in this is that the POP client only retrieves email from th inbox folder, and after conversion, this will mean only new emails. If the POP client's previous download of older email dissappeared (for whatever reason), a Web Mail client accessing the mailstore via IMAP would allow access to the ConvertedMail folder.

Regards, Paul