Not OP, but I think I could answer.
Traditionally, mail is uncountable. One can count letters and packages, but not mail. Thus "I received three mails" is currently grammatically incorrect, while "I received three pieces of mail" or "I received three letters" or "I received three packages" would all currently be grammatically correct.
It seems logical that email should follow the same rules of grammar. Thus "I received three emails" should be incorrect, while "I received three pieces of email" or "I received three messages" would all be grammatically correct.
But English grammar is not consistent. Email is a new word and the folks that use it have decided that it is countable.
I don't mind this, but it seems OP does.
My father was once driving with a friend when his friend, Dave, said, "Hey, look at that black Datsun."
My father immediately - and for no particular reason - lied, "All Datsuns are black. That's how they save money."
Years later, Dave wrote him a postcard with one sentence: I saw a red Datsun!
(yes, I'm aware of the Ford quote)