Just pushed new developer builds for all the platforms. Lots of little fixes and updates from the past 2 weeks. These builds have had little/no QA and are not an *official* release. We are running it as our internal mail currently.
The *big* change in this release is a new IMAP implementation based on Java NIO. This no longer requires 1 thread per connection. It also re-enabled IMAP IDLE which makes push email to mobile clients much faster.
IMAP NIO is off by default. To enable it please run:
$ tomcat stop
$ zmlocalconfig -e nio_imap_enable=true
$ tomcat start
Please let us know if you see any problems with this new IMAP impl.