Incompatible Plug-in disabled

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Install the latest version of Letter Opener

This message can appear after a system update and simply requires the latest version of Letter Opener.

Get the latest version from our download page.


To ensure that Mail functionality is not compromised by outdated plug-ins, Mail disables plug-ins that are not updated.

We provide a newsletter to inform our costumers about important updates.

  1. Go to Mail > Letter Opener for macOS Mail > Newsletter Sign Up
  2. Enter your email address and click the Join button.


Uninstall Letter Opener