> What could possibly take 30 business days to unsubscribe email? This is evil.
Companies can, and do, take out lists of subscribers and pass them to agencies to run campaigns for them, with potentially long lead times. Still stupid, but that's usually the reason.
Regarding standard, the List-Unsubscribe: header is sort-of that. It's not used much because there's little reason to - most clients don't do anything with them.
Gmail does use List-Unsubscribe: when you mark as spam a mail which has a valid List-Unsubscribe header, it will ask you if you want to unsubscribe instead, and will handle the unsubscribe request automatically.
Companies can, and do, take out lists of subscribers and pass them to agencies to run campaigns for them, with potentially long lead times. Still stupid, but that's usually the reason.
Regarding standard, the List-Unsubscribe: header is sort-of that. It's not used much because there's little reason to - most clients don't do anything with them.