Eh, that's the edgiest of edge cases, not something that should drive default functionality. Also easily addressed by manually marking the email as spam. The

Eh, that's the edgiest of edge cases, not something that should drive default functionality. Also easily addressed by manually marking the email as spam. The filter could treat that as a cue that the sender should no longer benefit from the address-book check. Better yet, store the flag as a visible field in the address book, so that you can turn it on and off yourself when you edit their contact information.