I'd like to report a bug that I have started seeing just today. Under below conditions, the draft being edited is automatically sent before clicking Send button.

1. When replying to the last message of a long thread (which is open in a tab -- i.e. when "tab view" is active)
2. Once one or several images have been pasted inline the draft message being edited
3. When switching to another email tab and returning to the tab where the draft was open, you find that the draft has now been sent (before you completed the message and explicitly clicked Send).

I believe I did not accidentally use any keyboard shortcuts that caused the email to be sent.

This happened multiple times in the same email thread.

Hope the above information would be useful to recreate the issue and troubleshoot.