Getting Started

Installing Letter Opener for macOS Mail

Follow the instructions on the download page.

Opening winmail.dat files with Letter Opener for macOS Mail

Winmail.dat attachments are automatically converted and displayed like any other email message in macOS Mail.

When Letter Opener converts a winmail.dat attachment, a banner appears on top of the email message.

Troubleshoot

Installer can’t be opened because it was not downloaded from the App Store.
Winmail.dat file is not converted.