TNEF

Pronounced tee-neff, and short for Transport Neutral Encapsulation Format, a proprietary format used by the Microsoft Exchange and Outlook e-mail clients when sending messages formatted as Rich Text Format (RTF). When Microsoft Exchange thinks that it is sending a message to another Microsoft e-mail client, it extracts all the formatting information and encodes it in a special TNEF block. It then sends the message in two parts – the text message with the formatting removed and the formatting instructions in the TNEF block. On the receiving side, a Microsoft e-mail client processes the TNEF block and re-formats the message.

Unfortunately, most non-Microsoft e-mail clients cannot decipher TNEF blocks. Consequently, when you receive a TNEF-encoded message with a non-Microsoft e-mail client, the TNEF part appears as a long sequence of hexadecimal digits, either in the message itself or as an attached file (usually named WINMAIL.DAT).

Webopedia Staff
Webopedia Staff
Since 1995, more than 100 tech experts and researchers have kept Webopedia’s definitions, articles, and study guides up to date. For more information on current editorial staff, please visit our About page.

Top Articles

The Complete List of 1500+ Common Text Abbreviations & Acronyms

UPDATED: This article was updated April 6, 2021 by Web Webster   From A3 to ZZZ we list 1,559 text message and online chat abbreviations to...

How to Create a Website Shortcut on Your Desktop

UPDATED: This article was updated April 6, 2021 by Web Webster   This Webopedia guide will show you how to create a desktop shortcut to a...

Windows Operating System History & Versions

The Windows operating system (Windows OS) refers to a family of operating systems developed by Microsoft Corporation. We look at the history of Windows...

What are the 5 Generations of Computers?

UPDATED: This article was updated on April 6, 2021 by Web Webster   Learn about each of the 5 generations of computers and major technology developments...

Random Access Memory (RAM)...

UPDATED: This article Updated April 6, 2021 by Web Webster   Random Access Memory (RAM)...

OEM – original equipment...

UPDATED: This article was updated April 6, 2021 by Web Webster OEM (pronounced as...

Best ERP Software for...

UPDATED: This page was updated April 6, 2021 by Web Webster   Enterprise resource planning...