I have pretty much the same problem which has persisted for over 36 hours now except the problem just happened without a reboot or any intervention from admin. This has happened before but the problem did rectify itself so never knew the reason why. I have tried removing all the settings from the email server parameters, saving,rebooting and then re-inserting but nothing. I've tried stopping and restarting the email server but this has little effect. The machine is fully patched up to date and not under any particular load.
Also, the active monitor sometimes shows that the smtp service is problematic. However, the raq is not used for sending emails - just receiving only.
Getting close to my wits end.... Someone must have experienced this before and know the answer....please...
I hired some outside support from computerhouse.com and they fixed the problem last night. The error was due to a permission error on a "critical sendmail file". The logs showed the the permission change happend when the server was rebooted. They fixed it last night but this morning when I rebooted it showed up again. I just got a email that they are looking into it again.
Stay tuned for more updates as they are available.