I have a very old Gmail account. For purposes of this discussion, call it sergey@gmail.com. I often get real email sent to addresses like sergey2000@gmail.com.

I have a very old Gmail account. For purposes of this discussion, call it sergey@gmail.com. I often get real email sent to addresses like sergey2000@gmail.com. By "real" I mean important stuff that people would miss if they didn't receive it. In the beginning, I used to follow up. I'd occasionally get a reply from the sender asking a question like "OK, thanks, could you send it to her for me?" I concluded that some people have a "horseshoes and hand grenades" attitude toward email addresses -- close but not exact is good enough. Maybe they can't remember all the digits in the address, so they put what they can remember and hit send.