Upgrade from version 1 to 2

Hi All I am upgrading from dovecot-1.2.17 to dovecot2-2.2.27_4. I configured version 2 from scratch. I have email in the maildir format. Would it be ok in theory if I simply copy over the email files from the version 1 server to the version 2 server or are there any hidden dangers here? Any problems with indexing?

Thanks for any advice