I’ve been a Fastmail user for years, having left Gmail. It works great and have nothing be but praise for them. I use my own domain with them so if I decide to leave it’s not an issue worrying about updating people with my new email.
This way - many different providers either lock that username away and throw the key (even you can't get it again; some give you the key instead of throwing away but no space in their home until you pay again) and some just graciously offer a free plan with that address whith little or barely any resources (which is actually great and very generious of them). Which ones? Google around and you shall find.