[Dovecot] Upgrade to a new system

Hello,

I have a system that I am preparing to update that currently uses dovecot for pop and imap (will have same ip as old system). In tests, I at times re-download data from the server if I have deleted or moved it in the client and the data is still on the server (just for pop). I am guessing the UIDs generated are different on the new system. Is there any way to check and see if they are the same on each system, and if they are not, how can I move that information over.

thanks,

Dan