Did you receive an email attachment named winmail.dat or winmail? Here’s a brief explanation of what this file is and instructions for opening it.

Winmail.dat files are sent by people using Microsoft Outlook as their email application. Under certain circumstances Outlook will encode attached files, like Word or PDF files, in this winmail.dat format.

Update May 2012: If you need to open winmail.dat files on your iOS device (iPhone, iPad or iPod Touch) try Winmail File Viewer which currently costs 99 cents in the iTunes Store.

Update February 2017: In November 2015, an iOS version of TNEF Enough was released by the developer of TNEF Enough.

Mac users can open the winmail.dat file using a free application (donations accepted) and extract the files hiding inside. Unfortunately, this application has a goofy name which is TNEF’s Enough.

DAT is a format used for storing data created from MPEG files using a VCD-authoring tool. DAT files can be played by Windows Media Player, Real Player, and a number of other players. Here are some problems you can solve by converting DAT to another format. You may receive winmail.dat files from the senders who are using Microsoft Outlook (1997, 2000, 2003, 2007, 2010). Winmail.dat contains all attachments and rich. Data File for Outlook 2019 Mac Where does Outlook 2019 for Mac store it's Data file? I used to routinely backup my Identity in Outlook 2011 for Mac but I don't know where to find what I should back up in the new version. This thread is locked. You can follow the question or vote as helpful, but you cannot reply to this thread.

Dec 16, 2019 Download DAT File Player Elmedia Player and play.dat files on your Mac easily. DAT Player for Mac. Top choice Elmedia 4.8 Rank based on 463 + users, Reviews(367) Get free website version. Olga Weis Dec 16, 2019. What's VCD.dat files. VCD stands for 'Video Compact Disc' and is a standard digital format used for storing the video on a CD. To prevent data recovery, file shredders overwrite the deleted data with a stream of zeros or randomly generated data. Many Mac file shredders are designed to comply with various standards for secure file deletion, such as the DoD 5220.22-M standard, which was published by the U.S. Department of Defense in the National Industrial Security.

Here are instructions on how to open the winmail.dat file:

• Save your winmail.dat file on your Desktop.
• If you use Mac OS X 10.6 or later then download the most current update of TNEF’s Enough version 3. If you use Mac OS X 10.5 then download TNEF’s Enough ver 2.2. If you use OS X 10.4 or earlier then download TNEF’s Enough ver 2.0.
• By clicking on one of these links, you’ll download a .zip file which contains TNEF’s Enough inside. Your Mac should automatically open the .zip file so you should see TNEF’s Enough sitting in your Downloads folder.
• Move TNEF Enough into your Applications folder.
• Double-click it to open, then go to the File menu and select Open…
• Select the winmail.dat file which you previously put on the Desktop.
• You’ll then see a window listing the embedded files which are the files that you actually want.
• Click on each file, one at a time, and click the Save button.
• Save these files to your Desktop or any other desired location.
• Quit TNEF’s Enough.

Open A Dat File Online

You’re done. You can now throw away the winmail.dat file since you’ve extracted all of the files from inside it.

Dat Files For Mac Files

Download Dat File Opener

If you’d like to read more about how and why this happens please read this Microsoft Support article or this other article. These articles also provide instructions that you can pass on to the Outlook user who sent you the winmail.dat file so he or she can make changes to no longer send you winmail.dat files. Essentially, they have to edit their record for you in their Contact list to indicate that you should only receive plain-text emails.