It's 32 bit Outlook right?

MAPI works straight up out of the box on Win2008 - no need to mess with it.

Otherwise, you may try the repair steps in Microsoft's support knowledge base article#813602 (see the related article "Repair Microsoft Office Outlook 2003 or 2007 Mapi") reprinted below:

In Windows\System\32 {or Windows\System}, rename the Mapi32.dll file (for example to mapi32.old), and then start the Fixmapi.exe program as follows:

Close all programs.

Click Start, and then click Search.

Click All files and folders.

In the All or part of the file name box, type mapi32.dll, and then click Search.

When the search process is complete, right-click the Mapi32.dll file in Windows\System\32 {or Windows\System}, and then click Rename. (Note: If mapi is in memory, you will not be able to rename it.  Click Ctrl-Alt-Delete and End Task on mapisp32. Verify it's not running before trying to rename it.)

Type Mapi32.old, and then press ENTER.

Click Start a new search, and then click All files and folders.

In the All or part of the file name box, type fixmapi.exe, and then click Search.

When the search process is complete, double-click Fixmapi.exe (or right-click and "Run as Administrator" in Vista/7) to start the repair process.

Follow the on-screen instructions to complete the MAPI repair process.

Thanks Ettienne,

MS Outlook was suppose to be 32 bit, but it looks like they installed the 64 bit version.

Even so, Thunderbird should have worked.  Ultimately they do need MS Outlook 32 bit, for which they do own licenses.

Unfortunately I can't try the fixmapi solution until all the users are off the system since its a TS.

Well 64 bit Outlook will not work.

Thunderbird might have been 64 bit as well, I don't think Thunderbird and Outlook play nice together.