Last time I installed a mail server was a couple of month ago. I consider mysql a pro, I feel pretty familiar on command line, working in this busines as a SysOp and Developer for a couple of decades. But one not just "set up a mail server". Saying "mail is not hard" sounds kind of cynical to me. You need to handle more than one setup, you need to consider compatibilities, you need to make it right, if you want to have a secure and reliable solution.

If your not in the busines of setting up mail servers every day: Mail is hard. As long as there is no download-and-run-solution for a mail-server: Mail is hard.