Inbound emails stopped working

[Shando]

Hi,
We have a Cisco asa 5540 firewall, and 2 exchange servers behind it and a brightmail 6.0.5 server, all emails get sent from the firewall to the brightmail then to the exchange servers, everything was working fine but all of the sudden inbound emails stopped working, we didn’t do any changes, all the services on the brightmail server are working including the IIs service, I made sure it is not an issue with the firewall, ISP, and exchange by bypassing the brightmail server, which everything worked fine with that test, we also called Symantec’s support and they did some tests and checked on the database with no avail.
We even reinstalled the software on a different server, but it is still not working. Can someone help with this please?

thanks...Shando<>

 

[Shando]

I forgot to mention that we have exchange 5.5 with the latest service pack.
thanks..Shando<>

 

[Shando]

Hi,
I finally managed to get the brightmail server to show that it is processing messages and I can see the messages coming to the queue folder, but still have no inbound email, I don't know where all the emails are going, what IP address should I put in IIS config for default smtp virtual server on the brightmail server? Anything else I should look for?
The kick back message the sender is getting is "550 5.7.1 Unable to relay for email@123.com"