Letter Opener

The winmail.dat solution

Some people still use Outlook. And whenever they send you something like an attachment or appointment, it shows up in your Mail with a winmail.dat file attached. (Ugh.)

But Letter Opener seamlessly converts all types of Outlook’s irksome winmail.dat files. (Hooray!)

Get Letter Opener Pro — Try it 14-days for free

Letter Opener Pro converts seamlessly winmail.dat file inside OS X Mail or Microsoft Outlook. The two most popular mail applications on OS X.

Download Letter Opener Pro for your mail application:

Letter Opener Pro

Available from our Store for $29.95.
Just click to Buy Now.


OS X 10.10 Yosemite or OS X 10.9 Mavericks. See OS X support details. Click here to view the release notes.


There’s no fuss with Letter Opener, no need to drag the winmail.dat file onto another application or call upon several programs to help you. Once Letter Opener is installed, you can forget about it.

Outlook compresses all of its attachments together into one winmail.dat file, leaving the rest of us scratching our heads as to what's inside. With Letter Opener the attachments appear like any others!

What a relief! This solves a recurring problem, that was a major irritation! It works flawlessly and seamlessly. You never even know it's there!

Ted O.

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