MS Outlook Web Access Exchange Server 2003

I've got an issue and I was wondering if you had any suggestions. Our power went out last night and I didn't have a backup battery on the Mail server. Most everything seems to be fine except some can't log into our email accts. I've tried resetting our passwords with no luck. Other users can get into their mail fine. I can get to the login screen, and then type my username and password, but it tells me to check my domain\username and pass. I'm getting some error like default microsoft exchange services.. critical state is stopped. I can get the exact error if needed. I was going to see I could log into the server remotely and try to fix this, but I don't know what all is involved. I'm not sure if I need to do a repair install or what?? I still don't know how quickly I could fix this. I need some expertise.