Alright, so we have an external IP block for our mail server and a few other machines, and we have a WAN interface ip.
Previously, our mail server traffic would be routed out of its own IP address to the internet. All of a sudden, our mail server traffic is instead being routed out of our WAN ip which has no reverse DNS. This is causing me major headaches getting mail through to AOL, Comcast, and a few other domains. I haven't altered the configuration of our cisco 2811 router/firewall in months and I'm not sure what would be causing this change. The nat statement for our mail server is such:
ip nat inside source static 192.168.0.9 65.121.x.x