> On the other hand, that person is leaking his information directly to me just because of typos when he fills out online forms.

I often get some misdirected emails because of a very banal name in my country.

When the email contains a thread history, I sometime noticed that the address was simply corrupted by a recipient, such as numbers getting dropped from the genuine address in their reply.

I guess some systems can't handle correctly numbers or other characters in email addresses.