[Dovecot] Blackberry suggestions?

[Ed W]

Hi, I'm not a Blackberry user, but we have some customers currently 
using an Exchange server with some kind of blackberry and interested in 
moving their service over to our dovecot 1.1 server

Does anyone have any notes or recommendations on getting a (UK) 
Blackberry to talk effectively to a normal Dovecot server, and are there 
any things to consider in order to get whatever features they are 
normally using on their Exchange link working on the Dovecot server? 
(It's just a small couple of person office on an Exchange server)

Thanks for any thoughts/tips

Ed W