Are all your flagged emails back? Do you want them gone? Mail plugins help make macOS mail a bit less awful. If your Mail bundles stopped working, it’s not hard to get them back up and running. The secret lies in adding a `
Supported10.13PluginCompatibilityUUIDs` entry in to any mail plugin bundle’s internal Info.plist file. You can then move the plugin back from the disabled folder to the main plugin folder.
defaults read /Applications/Mail.app/Contents/Info.plist PluginCompatibilityUUID
This reads the compatibility UUID and prints it to the terminal command line. You need this UUID to edit the Info.plist file. Starting in 10.12, you need to use the
XX.YY format as part of the key name. For example, here’s what the 10.13 version looks like:
<key>Supported10.13PluginCompatibilityUUIDs</key> <array> <string>CompatibilityKeyHere</string> </array>
Once you’ve done this, move the bundle back to the right folder and restart mail. The bundle should hopefully continue working.