I have been a lurker in MangoLassi.it forum as well. It's an IT community, similar to Spiceworks, infact, most of the people I see there are also in Spiceworks.
Just yesterday, I have had a chance to see how they, or at the very least, Scott and Romo was testing an email server...a fork of Zarafa. Its a good read for issues and what constitute an enterprise grade software, as scottalanmiller points out. I was wondering, is anyone here visited and also a member of their community?
Found these in the community/forum page:
Others will be just a mention of NS (specially as an alternative to Zentyal) but no review yet. Followed up scottallanmiller (the 2nd link) regarding his test.
On the 1st link (scroll to the presently 2nd to the last comments), there's one user, drewlander, who started testing NS but was not able to move forward, perhaps time constraint, and he tested again. This, I have not followed-up.