[CentOS] MS Exchange Replacement

Joseph L. Casale wrote:
> What is the closest open source mail server I can replace exchange
> with that provides the nearest equivalent in user experience?

Not open source, but I recently came across 'PostPath'
<http://www.postpath.com> - it claims to be the only 'True Drop-in
Exchange Alternative' - I believe parts of it are based on Postfix and 
Zimbra.

I've never used it, but would be interested in anyone that has ... as 
I'm looking for something that can work with Exchange, but without the 
'2nd class citizen' approach that Exchange gives non-Windows users.

James Pearson