I'm tired of moving spam mail to spam folders from which the system never learns. So it's time for me to try a new approach -- one that will give me the ability to not only block spam, but to monitor what is happening within my mail server in an easy manner and to solve an apparent 'missing' email problem for one of my mailbox users. (Actually it wasn't missing: it was going directly to the Spam folder. But the tool the users were using did not allow the spam folder to be easily read and it didn't properly learn what was and was not spam.)
To that end, I chose to drop the Axigen mail platform, which was problematic for me at best.
I had several goals with this upgrade:
Auto Learn if Spam is in the Spam mailbox or moved out to the Users Mailbox using a system wide learning tool
Disable Auto-movement of Spam mail to the Spam mailbox on a per user basis
Web based monitoring of where mail is going at all times
Multi-domain configuration with database backed aliases, etc.
Support for IMAP over SSL, POP over SSL, and SMTP over SSL
In search of solutions, I investigated Zimbra and Gmail. I would have liked to use Zimbra, but given how my network is setup, it just would not install. Zimbra is not designed to be installed within a DMZ without access to the internal DNS configuration. So this was not for me. As for Gmail, the privacy concerns about having a third party with access to my email was not to my liking. This to me is a jurisdictional issue. (By the way, I do have a Gmail account, but I use it as a backup, just in case my mail server has issues. This has happened twice in 20 or so years.)
In the end I went back to what I know. I know how to configure and use MailScanner. But I wanted to make sure I could monitor my email environment easily. Did MailScanner have a new tool to aid in monitoring? A quick search showed me that it did, via the MailWatch interface (and it was relatively current as well!).
However, since MailScanner is not everything, I still needed a mail transport agent (MTA). For this I chose postfix as I was also familiar with it, it was supported by MailScanner (albeit not quite the same way the postfix team envisioned). And there was a web based tool called Postfix.Admin that allows for management of multiple domains, aliases, etc. Then use Dovecot for IMAP and POP over SSL support.