Using the optimized form, we don't require anything but name and email. I find myself sometimes staring at a name which matches a name in our DB, but a different email. I finally thought to look in BBMS where they do have to provide a billing zip code. Zip code match! Aha! Same person.

It would be amazing if on our internal notifications we could get the billing zip as well - just to cut down on time spent being a sleuth. (Or just letting it become a new record until I have time to figure it out, leading to our development officers saying "why is this person coded new donor? They've been giving for years!")