Send Companion is an App Store approved and privacy-aware extension for Apple Mail on macOS Monterey (12.0) and higher, with the following features:

• Do you often write the same email fragments?
  AutoText saves your composed (localized) email snippets inside a convenient toolbar to reuse it over and over again. Just compose an entire email with a few clicks.
• Wish you ever had a second chance? With Review Alert you have!
  Review Alert delays your send action, allowing you to briefly review your email for the most common mistakes, like typos or sending the email from the wrong account.
• Based on keywords you define, Attachment Reminder will remind you of a missing attachment.
  This allows you to add the attachment even after you have pressed the send button.
  Never ever send a second email with "and now with attachment...".