You receive a "Currently your mailbox is stored on an older version of Exchange server" error message when you try to access Outlook Mobile Access

When you try to access Microsoft Outlook Mobile Access (OMA), you receive the following error message:Additionally, the following event ID may be logged in the Application event log:However, all your Microsoft Exchange Server computers are running Microsoft Exchange Server 2003.

This issue may occur if the following conditions are true:

• The Exchange virtual directory is redirected to a different URL.
• This second URL does not use HTTP. It may use the HTTPS protocol or other protocols.

When the Exchange virtual directory is redirected to a different URL, such as a redirect of HTTP to HTTPS, OMA cannot handle the redirect. The OMA virtual directory must communicate with the Exchange virtual directory by using HTTP.

To work around this problem, use the resolution that is documented in the following article from the Microsoft Knowledge Base:

817379 Exchange ActiveSync and Outlook Mobile Access errors occur when SSL or forms-based authentication is required for Exchange Server 2003

This behavior is by design.