I mean…do you plan on outlasting Hotmail? 15 years isn’t that long. Your choices are probably to do it proactively or to do it when your back is against the wall. There is no third option. I’m not going to be like one of those insane nerds advocating for running your own mail server, but if you care about email address longevity, mail at one’s own domain seems the only way to actually achieve that. These days, it’s zero effort to use Fastmail or Hey or something to get email at your own domain. They register it for you and everything! The hard bit is, as you say, moving everything. But, again, that’s inevitable.
