How can I change the new mail notification interval for OWA 2000 users?

The new mail notification polling occurs every 2 minutes by default. To change this value, open the registry editor (regedit) and navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeWEB\OWA. The key name is NewMailNotificationInterval. Care should always be taken when making edits in the system registry.

For more information on this and other OWA registry keys, refer to https://support.microsoft.com/?kbid=311342.