[Dovecot] Moving maildir folders between different RC dovecot machines

Is it ever necessary to delete any of the dovecot files when moving between machines from different RC versions?

I read all the RC notes from RC15 to 31 and didn't see any notes about this, but wanted to be completely sure.

Have some domains that I need to move from a RC15 machine to a RC29 machine.

Also later this month we plan to ugprade from RC15 to Release 1.. when it is out shortly.