I think you kinda have to update it manually everywhere, but that's why you get your own domain, so you only do it once. Personally, I discovered just how much

I think you kinda have to update it manually everywhere, but that's why you get your own domain, so you only do it once. Personally, I discovered just how much spam/marketing email I was getting when I only migrated the "important" things to my own so I'm currently running with two emails. As for alternatives, I have iCloud+ with my Apple One subscription I already pay for. That lets you setup five custom domains, with up to three emails each[1]. I think even if you don't switch yet, it's a good idea to change your domain name while you still can because most services ask for confirmation on the old email and we've all heard the horror stories with Gmail locking you out of nowhere [1] https://support.apple.com/en-us/HT212514 https://support.apple.com/en-us/HT212514