ENDIAN Firewall - Can not recieve email from Forefront servers starting in November

Hello,

I can't receive any email from someone who relays through a hosted Microsoft forefront server. Started on Nov 1st. Everything was fine up to Oct 31. Any emails from bigfish.com, frontbridge.com, and messaging.microsoft.com do not come through. No activity from those domains appear in the logs. The only generated NDR's are from the sending server acknowledging that the queue has timed out. No help there. Happening on multiple versions of endian 2.2, 2.2 rc3. I have no problem receiving email from anyone else. They claim to have no problem sending mail to anyone else. I was able to get a copy of the message trace summary from the sending machine and the only odd thing is the "To IP address" is 255.255.255.255. The delivery result is 4.2.1 unable to connect. I'm guessing that means that forefront is having difficulty with MX record lookups, but only for domains that use endian? I'm having trouble believing that.

I was wondering if anyone else was experiencing this or if anyone had any ideas?

Thanks in advance
-Brian