HTTP Form Based Authentication with Microsoft Exchange 2003

By default, Form Based Authentication requires SSL to be configured on your IIS but there is a way around it.

Here are the steps to configure FBA to work without SSL:

1. Open Registry Editor (regedit.exe)
2. Navigate to the following registry key: HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeWeb
3. Under the OWA subkey, add a DWord value called AllowRetailHTTPAuth and set its value to 1 (it doesn’t matter if you have decimal or hexadecimal selected).
4. Quit Registry Editorand restart IIS services.  You do not need to restart the whole server for this change, just IIS.