Viewing Mail, cursor causes display of HTML
A minor annoyance I want to stop. When viewing Mail on my MacBook Pro (Catilinlia), if my cursor rolls over an image within the message, a grey box pops up displaying a large blocks of HTML code. This usually obscures reading parts of the message. Why? I have to move cursor away from message body to see entire e-mail. How do you turn off this undocumented feature? If I wanted to view the underlying HTML code, there are other ways to accomplish it. Pop-up HTML blocks are not user friendly to reading mail.
MacBook Pro 13", macOS 10.15