One of the users in my office network sends (from Yahoo Mail) messages to other users. In this specific case, the receiver uses Incredimail (free).
The first user attaches files with (real) extensions of .PDF or .JPG or .DOC (MS Word 2003) and the other user receives all attachements with the extension of .dat. The file name is the original one. I can open the .dat file coming from .PDF with Acrobat reader, I can open the .dat file coming from .JPG with a graphic application, I can open the .dat file coming from .DOC with Word. I have no problem to open these files by their original maker application.
I can save the .dat files and change the extensions to the original ones, and then open the files by the appropriate applications, with no problem at all.
But, of course, there is something wrong. I hope you can give me a valid explanation and, if it is bad, tell me what happens and so I can correct the problem.
TIA,
John Sandu