[Dovecot] backing up maildir dovecot files

Hello,

I'm having to migrate servers. Both are dovecot2 systems. I'm wanting to copy over my mail store from one system to the other. I'd like to preserve dates/times of emails. These are maildir setups on both boxes, I'd like to be as transparent to the end user as possible. I currently have the first dovecot system offline and the second dovecot system is offline.

Recommendations?

Thanks. Dave.