After some difficulties I’ve been having with Postfix (mostly SMTP-AUTH), I decided to give Exim a try as my MTA. The switchover has been slightly painful, but much less than I would really expect. My biggest problem was with clamav not running correctly for a bit, but a reinstall solved the strange permission problems I was having. Those problems were actually from changes I had to make with amavis under postfix though, so I don’t feel too badly about them.
I did have a little difficulty with TLS though. Didn’t want to run on 465, and still doesn’t want to do tls_on_connect for some reason.
I was just trying my first mailman setup with exim, following the README.Exim4.Debian, things seemed to have configured correctly, and people can subscribe, receive approval, etc, but not post to the list. Well, they can post but the messages don’t get out 🙁 Not sure why, hope to work on that tonight now that I’m feeling better.