Letter Opener

The winmail.dat solution for Mac, iPhone and iPad

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!)

  • Browser attachment of a winmail.dat file
  • Displays nested messages
  • Adds appointments directly to iCal
  • Converts notes with incredible simplicity
  • Creates contacts in Address Book
  • Reads and delivers receipts

The easiest way to view winmail.dat

Converting winmail.dat files is just a double-click away. You can get this stand-alone version to convert pesky attachments that occasionally find your inbox.


Letter Opener Lite requires Mac OS X 10.7 Lion or higher to run.

Release notes

Our latest release is Mac OS X 10.9 Mavericks compatible! Click here to view the rest of the release notes.

Features Letter Opener Lite Letter Opener Pro
Convert winmail.dat attachments Check Check
Mac OS X Mail integration Check
Microsoft Outlook 2011 integration Check