Open Winmail.dat and extract ZIP files with just a tap.

A winmail.dat file is an email from Microsoft Outlook that can not be read by other email applications. It needs to be converted for the content to be accessible.

Letter Opener does that with a simple tap!

With over 10 years experience (and a special dislike for winmail.dat files) we made sure that working together with Microsoft Outlook and Windows users can be simple and seamless.

- Open Winmail.dat files and convert appointments, notes, contacts etc. to iOS native formats.

- Get access to all attachments in Winmail.dat files.

- Extract ZIP files to view the contents

- Export files to another app.

- Winmail.dat Premium: Access to attachments in winmail.dat files
- ZIP Premium: Extract ZIP files and get access to the contents

We provide direct personal support, so don’t hesitate to contact us if you have any questions or comments:

Thanks for helping us to keep improving Letter Opener!

What’s New

Version 2.2.3

• Bug fixes and improvements.

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

Ratings and Reviews

3.3 out of 5
656 Ratings

656 Ratings

Outhseprose ,

It does the job

It does the job once I figure out what I’m doing. I don’t know if it’s my ineptitude with electronics or if the page you open that just pinwheels until you hit the back button and “Voila!” there is the file is not normal. Once you get to the file, it opens right up! That’s all I really care about.

Saanich2013 ,

Not as Advertised

This app says it is available for the Apple Family Sharing. However, it is only the basic versions, which is basically worthless. The Premium version works well and I like it, but to get it you have to buy it “in-app”. The app designer has made this so when you buy the Premium version in-app it is not able to be Family Shared. Apple said if they would set it so the Premium version was a separate app, then this would solve the problem. So beware that you cannot family share this app, even though it says you can.

VirgQuest ,

Premium version works well

I own the desktop version of this software and got a license for the full iOS version during a recent promotion. The "lite" version of this app is pretty useless, but the premium paid version does everything I need it to do. No problems at all. Would definitely recommend for anyone who gets a lot of email attachments from Exchange users.


Letter Opener GmbH
9.7 MB

Requires iOS 9.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, Dutch, French, German, Italian, Japanese, Korean, Portuguese, Russian, Simplified Chinese, Spanish, Swedish

Age Rating
Rated 4+
© 2006–2019 Letter Opener GmbH
In-App Purchases
  1. Winmail.dat Premium $3.99
  2. ZIP-Archive Premium $3.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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