http://forums.pcworld.co.nz/showthread.php?t=86743
The Fixmapi.exe tool is included with Windows XP and Vista to detect and aid in resolving conflicts with Messaging Application Programming Interface (MAPI) files that may affect your ability to send and receive mail and faxes from other programs.
The file can be run from your C:\Windows\System32 folder
Fixmapi.exe does not replace the current mapi32.dll file if the file is marked as read-only.