Whats the best email service?
Really depends on how you define “best”, but maybe Fastmail if your priority is features and usability or Protonmail if you value privacy a lot.
I would love to selfhost, but my internet service provider blocks port 25…
Selfhosting email is generally not worth it in my opinion and doing it from a residential connection is pretty much doomed to fail right from the start.
IIRC, because of sealed sender, they can’t know who you’re communicating with, only that you’re using Signal at all.