I’m going through the same situation. Am using the ePO 4.5, it was working perfectly and all of the sudden it just stop sending traps. I still can received test traps from the ePO but not from the automatic responses. Let me know if you could find something out or someone had any idea where to check out what’s going on. Thanks.
I oppened up a support case, but things were put on hold since it turns out that when I upgraded to 4.6, I missed that it isn't supported with the OS that my ePO server is using (Windows 2003 Web). I will let you know if I ever get resolution.