On Wed, 8 Jun 2011 01:27:57 -0400, Steve Spence wrote:
That what I found with most the open source /Linux mail products that customizing and extending can be difficult and a lot of time and effort. The exchange is one of the easiest ways to roll out large scale web base email if just expensive in upfront costs.
Interns of Hotmail they initially use to use Solaris for the MTA and storage and FreeBSD for the web services ( Apache ) they suppose of migrated windows by now using windows products Again I think this highly customize solution which may not be very useful http://en.wikipedia.org/wiki/Hotmail
we went through a similar search for a high volume solution which we could customize and brand right now we using we high a hybrid of (exchange/Icewarp/Atmail/ two layers of spam filtering )
As far as commercial packages go, Surgemail is worth a look. Very affordable and insanely powerful and customizable. The support team is the development team. It's not uncommon for bugs to be fixed in hours to day and even new features requests to be added in days to weeks. Runs on practically any major OS you prefer... -Vinny