So long as "whatever Gmail uses" really means "whatever the IETF [or other standards body] RFC defines" and gmail just happens to implement that RFC, sure. Oth

So long as "whatever Gmail uses" really means "whatever the IETF [or other standards body] RFC defines" and gmail just happens to implement that RFC, sure. Otherwise, I'm not inclined to give an advertising company control over the worldwide opt-out process for advertising emails... The 24 hours vs 7 days thing doesn't bother me at all, frankly. I care about not getting your bullshit for the next decade. If you squeak 4 more in and then stop because you have (or claim to have) a bunch of nightly processes that all need to complete, fine.