Scalix 11.4 was released in late May and it looking more and more like an enterprise-ready product. Although currently in beta, they will have activesync support in June. Adding that to their NotifyLink offering gives some good options for mobile devices.
Other good updates include...
More stable Outlook client
Better CalDAV support
Overlaid calendars in webmail
I'm also very happy they decided to certify CentOS 4 & 5, giving full support for both...it is about time some vendors did this!
Check it out: http://www.scalix.com/forums/viewtopic.php?t=10789
