File Extension Library

.TNEF File Extension

  • Developer by: Microsoft
  • Category: Misc Files

What is an .TNEF file?

.TNEF file extension is created by Microsoft. .TNEF has been classified as Misc Files.

.TNEF is Transport Neutral Encapsulation Format

File generated by Microsoft Exchange email programs such as Outlook; appears as an email attachment for email clients that don't recognize Microsoft's proprietary TNEF format; may cause the text "application/ms-tnef" to appear in the email if the email client does not recognize Microsoft Exchange formatting.

NOTE: Transport Neutral Encapsulation Format files with the extension ".tnef" are rare. Instead, unrecognized Exchange messages are usually seen with the filename Winmail.dat (.DAT file).

List of all softwares that can open the Transport Neutral Encapsulation Format
Microsoft Outlook 2016
Microsoft Outlook Express
Apple Mail
Microsoft Outlook 2016

How to Open .TNEF file on different platforms

Open .TNEF File on Windows

  • Right-click a .TNEF
  • Left-click "Open With" > "Choose another app"
  • Select the program that opens .TNEF file and Select check box "Always use this app to open .TNEF files" Press "Ok"

Open .TNEF File on Mac

  • Right-click (or Ctrl + Left-click) the .TNEF file
  • Click "Open With" > "Other.."
  • Then choose another program from the app list and press "Open"
  • Select check box "Turn on" for "Always open in app"

Open .TNEF File on Linux

Right click on the .TNEF file, choose "Open with" and select a program from the list above

Open .TNEF File on iPhone

Select a file. If you don't see an application to open the .TNEF file, tap "Share" and choose the right app.
Method 2
Save the file. Then open the app «Files». Touch and hold the file, then release your finger. You will see a black menu bar. After that tap "Share" and select an application.

Open .TNEF File on Android

Tap the Settings icon on an Android smartphone, then select «Applications». Click the Settings icon in the upper right corner of the screen, to change the default apps.
If you want to open, edit, save or even convert .TNEF files on Android, then your best bet is to download one of the dedicated apps available on Google Play.

How to fix problems with .TNEF files

  1. You need to update the application that you normally use to open .TNEF files. Only the latest version of the software supports the current .TNEF file format
  2. You need to check the .TNEF file for viruses. To do this, you need to scan it with a popular antivirus (Norton, Nod32, Kaspersky, Dr.Web, etc.)