If you are worried that the contents of the letters can now be read by everyone who is not lazy, there is an option to protect themselves.
How to uninstall the GPG Tools plug-in on a Mac
The whole process will take less than a minute.
Step 1 . Exit the Mail application if it is open ( Mail -> Exit application ).
Step 2 . Go to the desktop, select Finder > Go to Folder … from the Finder menu .
Step 3 . In the opened line, enter / Library / Mail / Bundles.
Step 4 . Delete the GPGMail.mailbundle file.
Step 5 . Enter the administrator password if required.
That’s all. After restarting the Mail application, the GPG Tools plug-in becomes inactive.