I am having an issue converting .EML files to .MSG files.
The EML file represents a message with a message attachment. The message attachment contains an embedded .bmp file. When opened with Outlook, the bmp file is displayed as part of the body of the message.
I use MFCMAPI to convert the EML file to an MSG file. If this MSG file is opened with Outlook, the bmp file is displayed as an attachment to the attached message. Drag the message into Outlook, open the message and the message appears correctly with the bmp file embedded as part of the body of the message. The message in Outlook has a message class of type IPM.Note. This is the desired (correct) result.
I then use my program to convert the EML file to an MSG file. In my program I employ the same steps as MFCMAPI to convert from EML to MSG. This program is run on the same machine using the same converter library that comes with Outlook 2010. The program creates the storage the same way as MFCMAPI and uses the same parameters. It converts the exact same EML file to an MSG. The MSG file is opened with Outlook 2010, the bmp file appears as an attachment (as it did in the preceding paragraph). All attributes that using OutlookSpy I can see that the attributes are the same as the attributes of the MSG file created using MFCMAPI (as in the preceding paragraph). I now drag the .MSG file created with my program into Outlook 2010 and get a different result. The bmp file appears as an attachment to the message rather than embedded in the message. Also, the message class is set to IPM.Document.Outlook.File.msg.14 rather than IPM.Note.
I'm seeking ideas on what might be the cause of my program, that imitates the conversion by MFCMAPI, to produce different results when the .MSG is dragged into Outlook.