Question : Unable to access OWA

Exchange 2003
SBS 2003 SP2

One of our customers had restarted their server recently, and since doing so, both OWA and OMA isn't working.

When visiting https://mail.companyname.com/owa, it prompts to login, and when doing so you are presented with a "HTTP/1.1 503 Service Unavailable" error.

There are individual entries for each user in the event log stated below where their phones are attempting to access the Exchange server.

All Exchange/IIS services are running but unsure what to try next.

Answer : Unable to access OWA

This happens quite a lot and it's normally related to a failed or corrupt Windows Update.

What happens is there is a corrupt registry key that is over 259 characters long.

Because Windows doesn't have the permissions to the key it cannot remove/fix it.

The HKCRScan tool will provide you with the registry key that is over the 259 characters in length.  Delete this key and restart the services and it should fix it.