Guide to Migrate from Sendmail/Pop3/IMAP to Ubuntu Zimbra

[bertie_uk]

As far as I'm aware this is still valid and is the solution for migrating any Linux/Unix sendmail to Zimbra.

[Mistoffeles]

How does this IMAPsync utility deal with the problem of not knowing each user's password?

[Rich Graves]

If and only if your source and destination IMAP servers support a standard IMAP authenticate feature, then impsync can log on to any user's account with admin credentials. Zimbra, Cyrus, and certain configurations of dovecot, uw-imap, and courier can do that.