We are running a native Win2K3 AD environment with Exchange 2003. Recently the OWA has been chrashing (once a week for the past month). There are no errors in the logs and no other trouble except no one can reach the OWA page. The only change we had was new uses that access their mail through Entourage on Mac's.
In trying to fix the web site I've done IIS resets with no effect. I've tried stopping the website and restarting with no effect. The easiest solution is a complete reboot, but restarting all the Exchange servives also fixes the web access problem (for a week).