I have a client with thesame configuration who gets the messages stuck in
"pending" queue from time to time. I found a ost that claimed that killing
the "inetinfo.exe" allowed the messages to start flowing again. Seemed
pretty radical but it appeared to work. Have only done this once and don't
know if any collateral damage is/can be done by ending inetinfo.exe so
I haven't had the opporunity to try the following procedure yet...
How To Flush the SMTP Mail Queue in Exchange Server 2003
More info on IIS...
Merv Porter [SBS MVP]