Our company uses Exchange 5.5 SP4, configured to use OWA. We have conducted testing of OWA internally (accessing OWA using a "local-LAN" Internet connection) and from home and found things to work rather well.
However, recently we have had a couple of complaints from three or four users that say that OWA is not accessible from their home computers. But when testing their accounts from a local connection (office) and from my home computer, things seem to work perfectly.
My thoughts are that this could possibly be a browser issue, as the users in question are AOL Internet users. This theory is not rock solid though as OWA has worked for them in the past, just not consistently.
Do you have any ideas that may help to solve this mystery? I have checked configurations and permissions until I'm blue in the face, but still may be over looking something. I have heard of this very same problem from other industry professionals, but have yet to hear a reliable solution! Your help would be greatly appreciated!
So what happens exactly when they try to access it? You said it was inaccessible, but you didn't provide any details that could be used for research. So, I can therefore only offer general advice.
First, I would quickly test your AOL theory by having one of the affected users try to access OWA using a different system/browser (perhaps they can venture to their local library?).