How to mark a message as done
Within the "To Do" section of your Inbox, you can hover over the message preview and click on the button with a checkmark inside a circle.
You'll also find the same button on the upper right side of the email subject.
How to mark a message as to do
Within the "Done" section of your Inbox, you can hover over the message preview and click on the button with a plus inside a circle.
You'll also find the same button on the upper right side of the email subject.