Converting TNEF file attachments to Notes® file attachments

Transport Neutral Encapsulation Format (TNEF) is a Microsoft standard for tunneling rich data over the Internet to a recipient. Rich data includes Microsoft Rich Text Format (RTF) text, OLE objects, file attachments, and other application data such as Microsoft Outlook calendar data. Microsoft Outlook clients and Microsoft Exchange can be configured to format email for sending to recipients who use Microsoft Outlook. In such a configuration, Microsoft Outlook sends the RTF data as plain text and places all other objects into the TNEF stream, which is usually attached to the email as a file named winmail.dat.

About this task

IBM® Domino® uses the TNEF Converter feature to extract file attachments from the TNEF stream and attach them to an IBM® Notes® document as Notes® file attachments. The TNEF Converter runs on a Domino® SMTP server. To enable the TNEF Converter feature, add the following setting to the NOTES.INI file on the server:


The TNEF Converter can process TNEF objects in an S/MIME signed message, but doing so invalidates the signature. By default, the TNEF Converter does not process S/MIME signed messages at the server. You can use the following NOTES.INI file setting to force the TNEF Converter to process S/MIME signed messages at the server.


The TNEF Converter can not process objects in an S/MIME encrypted message because it can not decrypt the message on the server.

The TNEF converter can only handle clear signed messages. S/MIME clear signed messages are sent as a multiple part signed message. The first part of the multiple part signed message is the original message, which may in turn be multiple part. The second part of the multiple part signed message is the signature. Unlike an opaque signed message, the clear signed message's data is in the clear. The TNEF Converter can find and open the TNEF stream, extracting any attachments contained within the TNEF stream.