Do you want to return to that account?

If not, Temp mail works fine.

Also, Bug me not has user-submitted usernames + passwords to services. This works nicely.

I’ve used Port87 in the past. The user who created it promoted the service on lemmy initially. It worked (I paid for a few months).

Firefox Relay is meant for this. It can create a new mask in a single click, and it will forward emails to your actual address as long as you have it enabled. I’m not sure if you can send emails, but that’s rarely needed.

I’m not sure how (or really, if) they keep their domain (mozmail I think?) from being blocked by websites as a source of spam.

Looks like Guerilla Mail still exists. Been around for years at this point. No idea if there’s any controversy about them, but there are reviews out there giving them high marks.

Addy.io, proton simplelogin, … give you one time email addresses

I use Fastmail.