I threw in the towel after about 10 years but not because of deliverability problems. When I first started running an email server for myself and my friends and family, it was a great learning experience. And it kept being a good learning experience for a few years as I rolled out things like Bayesian spam filters and SPF.

But eventually it got stable enough and did its job well enough that I stopped messing with it to learn things. And then it became a job instead of a hobby: friends texting me because my ISP was having an outage and they couldn't read their email, rolling out critical security patches ASAP, coping with the occasional DOS attack, and so on.

At some point, I realized that I'd started to resent running it. It was eating little bits of my time for no additional benefit to me.

I also, as one does with age, started thinking about what happens if I die or become incapacitated: my friends and family all lose their email service the next time there's an outage that requires manual recovery.

So I moved it to a commercial email service and have zero regrets about the move. I make sure I've always prepaid for at least 6 months of service so that if something happens to both me and my wife, my friends and family will at least have half a year to make other arrangements.