Is there a reason why the sending of mail is restricted to buddies only? It'd be a real convenience if we could send mail to anyone in game without having to add them as a buddy in order to do so.
That's true... BEfriend is the verb. The nice thing about the English language, though, is that it's versitile enough for any word to become any part of speech.
But on-topic, +1 to this.
Of course, you could just add someone as a contact, send them mail, and then remove them from contacts... but that's time consuming and rude.