Not really my place to judge how your system is built, but double-checking an email is still subscribed just before you push it out from the queue isn’t impossible. At your volume, this will end up around 20 primary key requests per second, which is a decent database load, but then again for a company that needs to contact 2m customers per day it sounds like this wouldn’t break the bank.
Not letting people unsubscribe quickly is a conscious, commercial choice/tradeoff, not some kind of hard technical limit. Legislation can push this easily in a different direction.
Not letting people unsubscribe quickly is a conscious, commercial choice/tradeoff, not some kind of hard technical limit. Legislation can push this easily in a different direction.