The Microsoft Exchange Internet Mail Connector (IMC) creates a file and
copies failed messages to the file. The file has an ATT, TXT, or DAT
extension. The file extension assignment is done in the following manner:
- If an inbound conversion fails, the raw message is copied to a
file with the TXT file extension. For example, the file name
can be Att00xxx.txt.
- MIME messages. If a parameter is not found in the headers that
can be used as an attachment name, IMC creates a file with the
ATT file extension (either from the MIME Type configuration or
Content-Type header information). If the MIME Content-Type is
configured in the property page, the file with the ATT file
extension is used. If the Content-Type is not configured, the
file with the DAT file extension is used.
- If no file name information is detected for non-MIME messages
(in X-MS-Attachment header or Begin header) and the bodypart is
a UUENCODED bodypart, IMC creates a file with the DAT file
extension.