When I can tell it'll be awkward, I just make up some letters on the spot like "gj5@mydomain.com". It's easy enough to look for To:gj5 in your horded mail to find out what business it was.
I've done this too before, weird thing to have to do but sometimes people just don't get it. Although, nine times out of ten I get asked if I work at that business because the first bit of my email address is their business name.