archive all saved IMAP messages

I need to archive (i.e., send to another mail server) all messages saved on my mail servers. I’ve implemented for SMTP submission, but haven’t figured out how to archive messages saved by IMAP (like to Drafts, Sent, etc.).

How would I best implement this? Can I enable Sieve plugin for IMAP? Or, some other method? Like one way backup to archive server?

I really only need to archive the messages sent/saved by a user and not the messages received from other users.

Kevin