How to stop macOS Mail app from saving multiple drafts to Gmail

I was having a niggling issue when bouncing back and forth between the macOS Mail app and the web interface of Gmail. If I started composing an email in Mail I found that when I went to view the inbox via the Gmail web interface I was presented with a litany of (mostly) empty Draft messages. Annoying.

There was a simple solution which I found in Mail's Account Preferences. It is thus:

  1. Fire up Mail
  2. Go to Preferences...
  3. Select Accounts tab
  4. Select Gmail IMAP account
  5. Select Mailbox Behaviors 
  6. Uncheck "Store draft messages on the server"
  7. Save
  8. Life and your inbox are in harmony once again

The account preferences for draft messages should look like the following: