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To download Winmail.dat Viewer - Letter Opener 4 from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.

Winmail.dat Viewer - Letter Opener 4

By Atlan Creative GmbH

Open the Mac App Store to buy and download apps.


Letter Opener - Open winmail.dat, .msg and .xps files.
• Browser attachment of a winmail.dat file like other attachments
• Preview of winmail.dat using QuickLook
• Convert nested messages
• Convert Schedules, Appointments and Task for iCal
• Convert Contacts for Address Book
• Convert Notes
• Convert Delivery receipts and read receipts

Please refrain from sending your bug reports or feature requests using the App Store. Instead, to ensure a direct response from us send them to We’re always happy to help our users and receive their comments!

What's New in Version 4.0.0

• New Icon
• Bug fixes and improvements.

If you like Letter Opener, please consider leaving a review. That helps us a lot. Thanks!


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Customer Reviews

Exactly What I Needed!

One review complains that you have to buy pro to use this—that’s true. But it’s affordable and SO useful, as it does exactly what it’s supposed to. Definitely would recommend!

doesn’t do anything

You have to buy the proversion to actually open attachments. Rather lame look for a diffrent software which does it for free or cheaper then this one.

So useful

Does excatly what I need. Converts those unreadable winmail.dat attachments quickly and reliably. Well done.

Winmail.dat Viewer - Letter Opener 4
View in Mac App Store
  • Free
  • Category: Productivity
  • Updated:
  • Version: 4.0.0
  • Size: 14.2 MB
  • Languages: English, Dutch, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Swedish
  • Seller:

Compatibility: OS X 10.9 or later, 64-bit processor

Customer Ratings

Current Version:
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Top In-App Purchases

  1. Winmail.dat Premium$9.99
  2. MSG Premium$9.99
  3. XPS Premium$5.99
  4. File Extension Repair Premium$4.99