Letter Opener for macOS Mail For Mac

If you are receiving emails from Outlook users, the Mail.app will display their content as a winmail.dat file attached to the email. Letter Opener is a simple plug-in that is able to quickly convert the data and allows you to access the winmail.dat file content through a simple double click.

Letter Opener comes with its own installer package which puts everything in place. However, you will have to restart the Mail.app and provide the admin passkey to be able to complete the process.

After the installation, the plug-in will run in the background, without requiring any user interaction. In any case, if you need to update or remove the plug-in, the installer also places a Letter Opener entry in the Mail.app main menu: navigate to that area to manage the plug-in.

Each time you receive an email containing a winmail.dat file, simply double-click on the item and Letter Opener Pro will take care of the rest: the message content will be displayed in a new window almost instantly.

Besides browsing the content of the winmail.dat file, Letter Opener is able to add events to your Calendar.app, create new contacts, or read receipts. Moreover, the plug-in provides support for nested messages, so you will be able to have a quick look at the entire correspondence.

Letter Opener is one of those software solutions that solve small, but quite annoying issues: the fact that emails received from Outlook users are displayed as winmail.dat files.

Since the interaction with the plug-in is resumed to a simple double click each time you want to open an attachment, the process will feel very natural.