I have a Netvanta 3430 supplying T1 access to my office. I recently installed a SBS 2003 machine with Exchange. I set up an MX record with my ISP, but the SMTP port 25 is blocked somewhere, so email is not coming through.
Error: No connection could be made because the target machine actively refused it.
I believe this is in the NetVanta. Needs someone with some real pro in them, or this will be another (third this month) deleted question with no points... :(