[Grhm]

Originally Posted by BritTim

I am quite surprised there are email services that reject the use of destination addresses of the form whatever@username.fastmail.com.

Worse than that, elvey says addresses of the form something@username.usersown.tld are blocked, which, unless I've misunderstood, means any address with two or more dots after the @
Tell me this isn't true.
ALL my addresses take that form !