I am trying to send an email to someone and I keep getting an error message stating that it was rejected by their mail server with the reason of the RDNS entry being invalid for IP address xxx.xxx.xxx.13.
My MX record indicates xxx.xxx.xxx.10 for mail.mydomain.com.
The PTR record I have is xxx.xxx.xxx.13 for mail.mydomain.com.
I sent an email out to another email address and looked at the header. The header indicates that it was received from IP address xxx.xxx.xxx.13 and domain of mail.mydomain.com.
Why is my email continuing to be rejected when my PTR record matches the information found in the header?