I recently had a request from a client for a mass migration of Cpanel to Zimbra. I just wanted to share the following script in case anyone else has this same need.

https://github.com/bensnyde/cp2zim

Essentially the script queries for all email domains, accounts and passwords via the Cpanel API, resets to a temporary password for imapsync'ing, then reverts passwords back for seamless migration. Send me a message on github if you need any assistance.