AC Capehart/Mail Rank

I have two really smart friends who are building MailRank. I don’t know more than they’ve posted online or made inferences from their name, but I think they are trying to make email distinguish between the stuff you do care about (mail from your spouse) and stuff that’s not spam, but you don’t care about (mail from the bike shop, mail from your mom). If it works (and, to be sure, I’ve got no idea how it possibly could), I’d love to get a “biff” style notification of “mail I do care about”!