Set New Mail Notification Polling Interval
Outlook Web Access users using Internet Explorer 5 or later can choose to receive a notification message at regular intervals when they receive new e-mail. By default, Outlook Web Access will poll the Exchange server every 15 minutes to check for new mail. By adding the following registry key, administrators can change the polling rate to a different interval.
Warning Using Registry Editor incorrectly can cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.
For information about how to edit the registry, view the "Add and Delete Information in the Registry" and "Edit Registry Data" Help topics in Regedt32.exe. Note that you should back up the registry before you edit it, and you should also update your Emergency Repair Disk (ERD).
To set the polling interval for new messages: