ISA 2004 Stopping Outbound Emails!!
Posted on 2006-05-24
I been running ISA 2004 for well over a year without having any email problems, now ISA is blocking outbound email from all clients randomly. We are not running the firewall client, they are web proxy and SecureNat.
I rebooted the Exchange 2003 server and Symantec Gateway server and got flooded with old emails stating they were not deliveried in a time manner. I watched the live logging on the ISA and sent out several test emails to family and all were "denied" at the ISA level.
I did notice some email went thru, however for some users and some were denied. The only thing I noticed that was different between the two was the ones denied did not have a rule associated with them and the client IP was the outside interface of the ISA. The ones that went thru did had a rule and used our gateway IP as normal.