Hi We are running Exchange 2003 SP2, Windows 2003 SP2 Enterprise, in an Active/Active/Passive Windows cluster. Today, we almost had a heart attack because we thought someone had accidentally deleted the cluster service account. Luckily they hadn't :) But - I was wondering what we should do in case it HAD been deleted? What would have been the effects and what would we need to do to ensure there was no downtime, loss of service etc?

I dont know about avoiding downtime, but the Echange 2003 relies on Windows Clustering so I guess you would need to re-create it and assign the correct permissions : http://support.microsoft.com/kb/269229 How to manually re-create the Cluster service account