Making mailing lists nicer: Writing a mail extension for macOS with MailKit

MailTools, a new Mail.app extension, enhances the mailing list experience for developers by helping users avoid common mistakes like top posting and not wrapping lines. Utilizing Apple's MailKit API for improved security and stability, the extension checks emails before sending and warns users about potential issues. Although it can't directly modify the editor, MailTools aims to guide users toward proper mailing list etiquette. The developer created the extension using SwiftUI and SwiftData, overcoming challenges with Swift templates.