//Open winmail.dat files on a Mac

Open winmail.dat files on a Mac

enoughGetting an email from a Windows/Outlook user can come with a problem for those of us on Macs. Winmail.dat is a proprietary email file format generated by Outlook or a Microsoft Exchange Server that provides rich-text formatting and the problem is that the files can only be read by certain email clients. So unless you’re using Outlook or Express you might be out of luck.

The are a couple ways to solve this though. The first, and hardest, is to ask your Windows friends to stop sending them. Of course they probably don’t even know what they are so just get them to go into Outlook on Windows, navigate to Options > Tools > Mail Format. From the Send In This Message Format list, select either Plain Text or HTML, then click OK to save the new setting. Pretty big pain in the ass if you’re getting more than a few message with .dat.

The other way is to download a free program called TNEF’s Enough. It will allow you to open those pesky files hassle free. Just keep the icon in your dock and when you get an email with the winmail.dat file attached you can just drag it onto the icon to read it. Very quick and very simple.

If you come across something else please let me know.

2016-10-21T21:43:42+00:00November 22nd, 2012|Categories: Random Posts|19 Comments


  1. Lunga December 10, 2013 at 6:38 pm

    I don’t understand how to access the files once I’ve ran the winmail.dat file through TNEF. Please provide guidance.

  2. Linda November 4, 2013 at 6:46 pm

    Snap! Right on even in OS X 10.9. Thanks!

  3. Andrew September 28, 2013 at 9:34 am

    Many thanks!! worked like a charm

  4. Craig August 26, 2013 at 11:43 am

    Great piece of software. In my 30 years of using Macs, I’ve never encountered a winmail.dat attachment… until now! And it was a very important bid proposal for remodeling our home. So, I truly appreciate your service in providing the TNEF info! It opened instantly on my OSX.8.3.


  5. BERNARD MORSINK August 22, 2013 at 10:48 am

    How can I open the Win Data File directly without havong to save it in Downloads to avoid the extra step.
    When I drag the Win Dat dile to TNEF and try to open it the only option I get is to save it in Finder and then open it.
    Aside from this the program works great!!

  6. Vladimir August 21, 2013 at 10:13 am

    Thanks for help, app TNEF Enough works perfect.

  7. Colin July 15, 2013 at 10:05 pm

    Great App, works perfect, Thanks

  8. Sonja July 10, 2013 at 12:38 pm


  9. Bob July 4, 2013 at 11:22 pm

    Thx a lot, Glenn! This instantly worked like a charm on my 2009 MBAir with OSX 10.8.4 and Mail 6.5 🙂



  10. Marius June 26, 2013 at 5:23 pm

    Thz… you save my.
    Marius for Milano

  11. Stephen May 29, 2013 at 9:19 am

    Thank you! We’ve just moved to Macs, and encountered an immediate problem with a photo attached to an email. Your program fixed this immediately.

  12. Caroline May 21, 2013 at 2:48 am

    You have solved my problems that I have been having for last 5 months, downloaded another apps before but didnt work. This one work perfectly and efficiently.


  13. Peter Dunajewski May 15, 2013 at 1:54 pm

    Thank you for the info regarding TNEF’s Enough (DAT file reader)
    It worked great, solved my problem.


  14. Spanners May 7, 2013 at 11:29 pm

    Massive thanks! This worked perfectly. And I advised my client to change their mail settings.

    • Glen Canning May 8, 2013 at 12:10 pm

      Glad you found it helpful.

  15. Perry Simpson March 27, 2013 at 10:25 am

    Thank you – worked fine, but you need to download the correct version for your MAC – see http://www.joshjacob.com/mac-development/tnef.php



  16. Thomas Cokenias March 20, 2013 at 7:40 pm

    Thanks for the free TNEF – worked fine for me on my winmail.dat attachment

  17. Glen Canning March 6, 2013 at 6:43 pm

    Sorry your having a problem with it Bill. I’ll ask some of the guys I work with and see what we can come up with.

  18. Bill Goodin March 5, 2013 at 3:31 am

    I have been unsuccessful using TNEF Enough to open winmail.dat file attachments to emails on my MacBook Pro running OSX 10.8.2. Can anyone help ?

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