I recently updated my MIAB, in the process I changed the IP.
Prior to updating I checked that the new IP wasn’t blacklisted. Unfortunately after updating email sent from MIAB are blocked (550 5.7.0) by Proofpoint (used by Apple for iCloud).
I thought that the IP was probably blocked because of some previous owner misuse. But here is the response from Proofpoint support:
The listing is due to invalid or generic PTR (reverse DNS) Record for the IP. The PTR record designates ownership and authorized use of the IP. The IP needs to be given a fully qualified domain name which resolved back to that IP.
For Example: mail.domain.com
Also, if the PTR starts with either: mail, mts, mx, out, smtp, that will help resolve the issue.
Please feel free respond to this message once the PTR record has been fixed, and the IP will be re-evaluated by the Threat Operations Team.
My glue records are set correctly, and everything is green in MIAB. They don’t wan’t to remove the block. Are they suggesting that the issue is the actual domain name of MIAB box.xxxxx.xxxx? Should I just try to change the primary domain.
What do you guys suggest?