YMMV. I've also ran my own since 1998. It's worked almost flawlessly from the start. A stock Debian system that I've kept up to date just keeps on ticking.

The only trouble I've had has been sporadically with Hotmail. Still don't know why, I get the bounce and contact the recipient from somewhere else. Even Gmail has these problems from time to time.

I just wanted to stick in another datapoint in the discussion, so not every post is about how awful email is. Sometimes it just works.