Apple expert Bob Gendler discovered that the Apple Mail app available on macOS stores leaves a portion of users encrypted emails in plaintext in a database called snippets. The issue affects all MacOS versions, including the latest Catalina. The company did not provide a timeline for how it plans to address the issue. The expert proposed the following three ways to disable these processes from scraping messages from Apple Mail from the app and Siri Suggestions folder in the user-level Library folder, which contains potentially important database files.”]
Source: https://securityaffairs.co/wordpress/93675/security/apple-mail-encrypted-emails-plaintext.html