I was having the same error.. but I asked for support to symantec.
And first they began to monitor the process to do this they use the CONFIGURATION AND LOGGING TOOL, but first they change the interval of time of the sd.email.Monitor and the sd.email.InboundManagement.
You can go to your servicedesk server and at the taskbar is the servidesk icon .. click right button, choose server-- local server and find your sd.email.InboundManagement
right click and edit Schedule to change the interval to 1 minute 00:01:00, do the same to the sd.email. monitor. For each sd process you can change the Logging level and there also use the Consol View log.
so if you have a configuration error you will see it on that log.
I hope these help you to find the error.