I self-hosted for a while in the early 2000s. It was a hassle. My box got hacked -- I'm sure I missed a security update or something -- and while I didn't lose any data because of my obsessive backup paranoia, it was enough of a Thing that I just punted.

I used Gmail for Domains for a hot minute, but never really liked it very much. Soon I found Fastmail, and I've been using them ever since (so about 13 years now).