NEW: macOS Sierra compatible
What is WinDat Opener?
WinDat Opener is a program for Mac OS X that extracts attachments from TNEF (winmail.dat) format files. It's the most popular and highest rated TNEF decoder on the app store.
Windat Opener is also available for the iPhone and iPad; for more information, see here.
Why WinDat Opener?
WinDat Opener is the easiest way to deal with those pesky winmail.dat files you keep on getting as attachments sent from Windows machines. But WinDat Opener is also powerful:
- Works with any email client. Just drag-and-drop winmail.dat files from anywhere - WinDat Opener does the rest
- New in version 2.1: Decodes embedded Windows Mail notes
- New in version 2.1: Windows "code page" support. WinDat Opener now decodes winmail.dat files that use Windows "code page" encoding for non ASCII character sets. Now data in encoding including Korean, Thai, Chinese, Arabic, Turkish, etc are all decoded
- New in version 2: Decode contact (vCard) and appointment (iCal) information embedded in individual data fields within winmail.dat files rather than attached as files (see the FAQs for more information)
- Decodes all TNEF format (winmail.dat) files
- Highest rated and most popular decoder on the App Store
- Simple drag-and-drop operation
- Unlike other TNEF decoders, WinDat Opener preserves attachment dates, making it easy to keep track of file versions
- Allows files to be opened from within WinDat Opener, allowing the contents to be examined without copying the attachment to a new location
What are TNEF files?
Microsoft e-mail programs written for Windows, such as Outlook, sometimes send e-mails in the Transport Neutral Encapsulation Format (TNEF). Most other e-mail programs, including Apple Mail and Microsoft Entourage, do not understand TNEF. If your e-mail program doesn't understand TNEF, instead of seeing the e-mail and/or attachment, you may only see an attachment named "winmail.dat" or "Part 1.2" that you cannot open. Also, sometimes you may receive a TNEF attachment with a generic name such as ATT00008.dat or ATT00005.eml instead. While almost all attachments named "winmail.dat" are TNEF, you could receive non-TNEF attachments with names ending ".dat" or ".eml", or which are named or labeled "Part 1.2".
WinDat Opener for the iPhone and iPad
OS X 10.6.6 (Snow Leopard) or later