Email aliases , pgp and e2ee

That sounds like a misunderstanding. A PGP/GPG-Key is bound to an email address. Part of it’s purpose is to prove an email is actually written by the owner of that address. If you have an PGP/GPG-Key for myrealidentity@emailprovider.com then you should use it only for email communication for this address. If you are using an alias like myalias@emailprovider.com then you have to create a PGP/GPG-Key for that alias and use it for all communication using that alias. Using myrealidentity@emailprovider.com PGP/GPG-Key for myalias@emailprovider.com would do two bad things: * It would reveal that myrealidentity is most likely behind myalias. * It would not ensure that myalias is actually myalias.