A couple of days ago a customers account here was compromised about two PM and used to send about 40,000 spams out before I shut it down. I managed to delete the majority of them from queue before they were processed but some got through.
In response, Comcast black listed out entire domain rather than the one customer all the spam came from.
I’ve already talked to Comcast Security and have been told it will take them 24-72 hours to remove the block. The ticket number is #NA250519982.