Block email using contacts

[Sloth]

I would love a Labs plugin that allows me to to block incoming email
based on my Contacts List. First we'd need a second Contacts category
named "Informal" that would cover stuff like newsletters and zines
which are not correspondences. And Formal contacts would be regular
correspondence, friends, family, work.

Then just use a block filter similar to Google Talk that prevents
anyone who is not on my approved Contacts list to send me email.

[estienne]

Excellent idea. In fact, you could have a flag for specific group(s),
and a flag if a person is just present in the address book. If it's
not present, I would sent it to "probable spam" folder, in my case
anyways.