I have been seeing more of these types of bounceback messages (IP address changed for example):
mail.test.com #550-Your message was rejected by this user and was not delivered. 550-Reason: Your IP address [18.104.22.168] appears not to be an email server. 550-Protection provided by: MagicMail version 1.3.5 (http://magicmail.linuxmagic.com) 550-For more information, please visit the URL: 550-http://www.linuxmagic.com/best_practices/check_dynamic_reverse_dns.html 550-or contact your ISP or mail server operator. 550 ae9e5e74-0ad7-11e3-b831-0050569008a5 ##
We have all of the DNS records set up for our e-mail servers and smtp outbound relay. Our MX record actually points back to our Barracuda Spam/Virus Filter in front of our Exchange server. The IP address that the message is referring to is the IP address assigned to our WAN on our Firewall/Nat device. Our default gateway address in this example would then be 22.214.171.124
What do I have to set up so that these messages are delivered? Do I set up a fake MX record pointing to the default gateway? Add another A & PTR record pointing to the WAN IP address? Is there something in our internal configuration that could be incorrect? No records are set up for the gateway address now, just the assigned IP addresses for each of the outbound services. All servers are Windows based. Primary e-mail server is Exchange 2007.