Using New Outlook on Windows for professional communication and productivity
Yes, it's absolutely crazy, the "edit message" feature only shows when you open an email in its own window, then collapse the ribbon then expand the "kebab" (three-dot) menu at the end of the ribbon [ie not the one within the message body, the one just below the windows titlebar].
This function "edit message" is not in the help system, nor does it appear in the "all commands" menus in the customise ribbon.
This is still not a "yellow sticker" feature but it will do. I wonder why MS don't seem to want to incorporate this oft requested feature?
[image upload also fails for me.]