Fix Mail Plug-ins Enable/Disable Issue on macOS Mojave

mail.appmojaveplugins

I have two Mail.app plug-ins installed: "GPGMailLoader.mailbundle" and "Smallcubed MailSuite.mailbundle". Currenly, GPG is enabled, and works, and MailSuite is disabled.

However, when I toggle either plugin (i.e. MailSuite to on or GPG to off), and restart Mail, the change hasn't taken. So I cannot use MailSuite, nor disable GPG.

I have tried:

  • Reinstalling MacOS Mojave in-place (did not fix).
  • Creating a new user (everything works for new user).

How can I further investigate this?

Best Answer

Eventually I moved my ~/Library/Mail folder to the Desktop, reset mail "to factory settings", then re-imported all messages from the moved folder. It took about a day, including the backup I did first.

Following the above "reset" instructions involves deleting ~/Library/Containers/com.apple.mail/. When I was perusing the new ~/Library/* and ~/Library/Containers/com.apple.mail/* setup, after relaunching Mail, there were differences before and after, in particular which items lived in the container and which lived in the real ~/Library. This may be a clue to a cause, but at least there is now a sledgehammer solution.

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