i have a similar situation. i've "known" this guy for ~10 years now, all the way from him signing up on a random dating site, to the present where I'm getting e-mails about his mortgage, and school info e-mails regarding his kids :D
I used to respond to the ones that were obviously from a real person, imploring them to tell him he keeps getting his e-mail wrong, but no dice, so now i just respond "wrong e-mail address" and hope that sorts it out.
I used to respond to the ones that were obviously from a real person, imploring them to tell him he keeps getting his e-mail wrong, but no dice, so now i just respond "wrong e-mail address" and hope that sorts it out.