I'm currently running a Snow Leopard Server, and trying to get anything useful working with the v1.1 version of Dovecot bundled with it is as pleasant as banging my head against a brick wall.
Dovecot's extremely sparse documentation has a lot of mentions of horribly-crippling bugs (specifically with public mailboxes and permissions) in 1.1 that were only fixed in 1.2. Which is not helpful for me since Apple has their own frustratingly-special blend of dovecot build (1.1.20apple0.5) for Snow Leopard Servers.
So, does the new Lion Server have enough Dovecot functionality to make it worth using?
Best Answer
Dovecot 239 is how it's listed by Apple as open source that was shipped with Lion 10.7 Build 11A511.
You can see lots of nice version and source code information at http://www.opensource.apple.com/release/mac-os-x-107/ in case the 239 doesn't match the real version of the package.
If you want to compare the current with past versions, many versions of OS X are listed at http://www.opensource.apple.com/