PC MAPI: Attachment Name Must Retain 3 Letter File Extension

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Article ID: 130321 - View products that this article applies to.
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Microsoft Mail for PC Networks attachments that are sent from simple Messaging Application Program Interface (MAPI) applications should retain the three letter file name extension as described in the Microsoft Windows 3.x registry database. If the three letter file name extension is not maintained, the application will not be launched correctly by accessing the icon associated with the object in the Microsoft Mail for Windows. Examples of these extensions include .DOC (Word documents), .WKS (Excel worksheet), and .WRI (Write document).


If the three letter file name extension is not maintained in the code for the MapiFile.FileName field (for Microsoft Visual Basic) in the MapiFile structure, the following error will be returned from the Windows client:
No application is associated with the attached file FILENAME.EXT.
Use the File Manager to create an association.
This error will occur even if Mail appears to display the application's icon that the file belongs to correctly. This information will appear correctly because the information for the icon object is in the system attachment WINMAIL.DAT. However, Mail does not use WINMAIL.DAT to launch the application associated with the file. Instead, Mail uses the standard associations found in the Windows 3.x registry database.

NOTE: MapiFileDesc is the equivalence of MapiFile in C.


Article ID: 130321 - Last Review: October 30, 2006 - Revision: 1.1
  • Microsoft Mail for PC Networks 3.0
  • Microsoft Mail for PC Networks 3.2
Retired KB Content Disclaimer
This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

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