If you want, you can start by customizing my mutt config:
http://hg.bsdroot.lv/aldis/dot.mutt/
Here's howto setup postfix relay:
https://wiki.bsdroot.lv/postfix:relay
Not sure how good it works, because, as always, I wrote it from my memory, after I configured my desktop pc to relay mail via my mailserver.
Probably next time, I lose my postfix config, I will fix bugs if any....
Or you can give me feedback (no much hopes, I will jump in and fix and help with everything, since I'm pretty dam busy right now, but it never hurts)
You can report wiki bugs @
https://bugs.bsdroot.lv/