.MS-TNEF File

The ms-tnef file extension is related to the Microsoft Transport Neutral Encapsulation Format.

The Microsoft email clients Exchange and Outlook use the file format called Microsoft Transport Neutral Encapsulation Format (MS-TNEF) to send email messages in Rich Text Format (RTF).

By default, Exchange and Outlook send email messages as if they will be received by other Microsoft email clients, extracting the formatting out of the original document and encoding it into a TNEF block. They then send the message in two parts: the first part is the text, while the second is the formatting.

An ms-tnef file extension is mainly associated with the Microsoft Transport Neutral Encapsulation Format used by e-mail clients.

How to open:

Use compatible tools to work with *.ms-tnef files.

How to convert:

Probably can be exported to other formats.