Known issues with Microsoft Office automation.
AutoIt provides a powerful integration and manipulation tool for the MS Windows environment and the WinAPI. Some features of Microsoft's Windows and Office products are proprietary and cannot readily be manipulated. Sometimes workarounds are required. It should be noted that some of these issues change over different versions, resulting in "unexplained" errors or unexpected behavior. This pages is dedicated to identifying those issues, provide explanations and list solutions or workarounds.
Microsoft Transport Neutral Encapsulation Format or TNEF is a proprietary email attachment format used by Microsoft Outlook and Microsoft Exchange Server. An attached file with TNEF encoding is most often named winmail.dat or win.dat, and has a MIME type of Application/MS-TNEF. The official (IANA) media type, however, is application/vnd.ms-tnef. Fronm this page: Wikipedia.org Transport Neutral Encapsulation Format