I use FastMail at home, but we have G Suite at work. The worst is when opening a new message from a mailto: href, I used to be able to start typing as soon the text box appeared. Now I often end up sending a (nearly?) blank message, which I luckily have always caught with the undo feature (but still!). I don't know if it's catching my return after the greeting and triggering the send button or what, but it's annoying!