Hi Folks, I'm running Exchange 5.5 on a Windows 2000 server. I have a number of messages stuck in my outbound queue in the IMS with either "Host Unreachable" or "Network Error during Host Resolution" errors. I can ping the recipients mail server, use nslookup to find the MX record and can reach the address through my hotmail account but Exchange can't deliver them. I have switched DNS servers several times, but no luck. The problem only seems to affect a small number of messages and I can't see a patterns as to which messages get stuck and which get through. Any ideas? Martin Buschbeck