Comment by jeffbee

"It goes without saying that our messages are not spam" haha no. I don't know what it is with these people who think their god gave them the inalienable right to send messages without rate limits just because they are signed with DKIM. The most likely explanation for why that site "School Interviews" got rate-limited is people marked their junk as spam and their sending IPs got bumped down into the bozo quota. And the most likely reason for people to have marked them as spam is they failed to do verified double-opt-in and just started spamming away at whatever address their customers mistakenly typed.