I am pulling my hair out with this one and have been troubleshooting for days. We are set up with SBS 2003 and we cannot send email to a certain domain nor can I tracert to it. The email hangs in the exchange queue for a few days before spitting out a 4.4.7 NDR. We can send email fine to everyone else and the failing domain can receive emails from everyone else. I have spoken with them as well as our ISP. Our ISP can send email and tracert to them fine so something is happening on my end. Tracert results are similar to this...
220.127.116.11 (external gateway)
It then does a lot of request timeouts and fails. When I tracert to any other domain, it does the first 3 routes and then connects so I am not sure why it is going through all those 10.100.x.x routes. I thought it was hung up for some reason at my router but after talking with the manufacturer and double and triple checking everything is set up properly as far as we can see. It is a SnapGear 300 device.
Also, I am not relaying nor and I do have reverse DNS. If anyone can please help in any way it would be greatly appreciated!