Comcast Throttling my mail server. New IP, postfix settings well below Comcast sending limits
Hello, we recently added a new mail server IP 184.108.40.206
I've checked the postfix logs and it appears every email going to a @comcast.net or @comcast.com email address is throttled said: 421 4.1.0 220.127.116.11 Throttled - try again later. Please see http://postmaster.comcast.net/smtp-error-codes.php#RL000001 (in reply to MAIL FROM command)
I am having no issues with any other email domains.
I have a custom transport rule that only allows our emails to be sent to comcast addresses under the guidelines comcast has set (1 recipient per email - 20 emails within a certain amount of time, etc).
However, once I turned the transport rule on, I have literally 3 emails go out to comcast addresses before we started getting throttled.
Its a new IP so I assume that is the issue,.
Could someone please unflag us, or whitelist our IP for sending to comcast addresses?
This server strictly sends reservation confirmations. Our customers are waiting for these confirmations