Mac App Store

Mac App Store is the simplest way to find and download apps for your Mac.

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

Winmail.dat Viewer - Letter Opener Lite

By Atlan Creative GmbH

Open the Mac App Store to buy and download apps.


Letter Opener Lite - 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 3.0.2

• Squashed bugs and beat the snot out of a number of crashers

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


Screenshot 1
Screenshot 2
Screenshot 3

Customer Reviews


After deciding to go Mac rather than PC as a result of the mess created with Windows 8 I had problems with Outlook based email attachments. I thought Microsoft still had their hands around my throat when I could not open important word and Excel Files on the Mac or iPad.

Tried different Pc outlook configurations but could not get a consistent faolsafe way of always getting files to open correctly.

This app sorted everything out. The files always get through and it’s easy to set up and launches automatically when needed.

I only have the lite version but never found the need to see what additional features are in the full one.

This works for me!

Opens .DAT email attachments on a Mac

Great, handy little tool that allows me to open .DAT attachments sent from Windows in Apple Mail.

Really useful as we work with both Windows and Mac clients.

Very easy to use and had no bugs to date so happy to write a review.

Great application, very useful for business

This is a very simple app that works flawlessly. It’s a key tool in my kit for working with Windows clients.

Winmail.dat Viewer - Letter Opener Lite
View in Mac App Store
  • Free
  • Category: Productivity
  • Updated:
  • Version: 3.0.2
  • Size: 6.8 MB
  • Languages: English, Dutch, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Swedish
  • Developer:

Compatibility: OS X 10.7.5 or later, 64-bit processor

Customer Ratings

Current Version:
All Versions:

Top In-App Purchases

  1. Winmail.dat Premium£7.99
  2. MSG Premium£7.99
  3. File Extension Repair Premium£3.99
  4. XPS Premium£4.49

More Apps by Atlan Creative GmbH