I know a lot of people use sendmail on a Unix box, and also qmail is the "popular" alternative. And that Courier is sometimes regarded as the alternative to qmail (because it supports qmail). But how does Courier compare to other email systems?

I came across a commercial product called DMail (http://netwinsite.com/dmail_first.htm) which seems to be a close functional equivalent of Courier. I've also met another product called IMail (http://www.ipswitch.com/Products/IMail_Server/index.html) in my current job, which is also functionally similar, though it runs on Windows NT whereas DMail runs on a larger number of platforms, including BSD and Linux.

I realize this is a Courier-oriented mailing list and the answers I get will therefore probably be a little biased, but has anyone had any experience with DMail (or IMail) and how do they think it compares to Courier?

Wade.