PS: My father-in-law has been dead for several years, and he's still getting mail.
In spite of our best efforts.
Would you like to come cast his vote in the next election?
Imagine what kind of mail we could generate for him if we tried! In fact, I know of a fictional character that was created by a group of fraternity boys. This "person" not only got personal mail for several years, but his wife and child got mail too! Every so often, one of the brothers would spend a pittance and send something in to renew interest. He had return mail labels, a magazine subscription, and so on.
If you're talking about preventing large-scale fraud, using mail to prove identity is not your friend.