Resolving Problems with Forms-Based Authentication

If you're using forms-based authentication but not requiring SSL on the back-end server, OMA will work but Exchange ActiveSync won't.

If you're using forms-based authentication and want to require SSL on the back-end server, to make OMA work you'll have to use either Exchange System Manager (ESM) or IIS Manager to create a new virtual directory on the back-end server.

If you're using Exchange ActiveSync and you want to use forms-based authentication or require SSL on the back-end server, you'll have to use IIS Manager to create a new virtual directory. You can't use ESM because it copies the flag indicating whether forms-based authentication should be used from the existing virtual directory. The Microsoft article "Cannot Access Exchange Server 2003 by Using Outlook Mobile Access When the Exchange Virtual Directory Requires SSL or Uses Forms-Based Authentication" (http://support.microsoft.com/?kbid=817379) explains how to use IIS Manager to create a new virtual directory.

After you create the new virtual directory, you'll have to set the HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesMasSyncParametersExchangeVDir registry subkey (of type REG_SZ) to point to the alternative virtual directory.