The client is running Server '03 and several versions of Outlook clients. The issue does not seem to follow any particular user, version of Outlook, or time of day. I don't see a pattern anywhere. So, either *all* the clients have an issue or the server has an issue. I see no warnings or errors in the server's Event Log. The client runs with client machines Windows Firewall active. Each client machine has the server machine at a 'fully trust' setting. I've got two guesses: 1. Outlook operates more consistently with some sort of firewall exception, although I'm not sure why this would be. 2. The server is expected to run in domain, file, exchange, internal web, and external web capacities. It's a Celeron 2GHz with 512MB RAM. I think Outlook may be 'timing out' server requests on occassion, then kicking the user into 'offline mode'. This is one of those I could chase for hours and not make progress. Anyone have any ideas?