change Flag names in Mail
‘Red’, ‘Green’ and ‘Yellow’ aren’t particularly meaningful ways to categorise messages, but changing the names to something more useful can make the ‘Flags’ feature a handy tool.
The procedure is quite simple, but the first thing you have to do is actually flag a couple of messages:
1. Flag some messages (one of each colour if you want seven categories):
2. Next, go into the sidebar in Mail. Click the little disclosure triangle:
3. Click on one of the names and press ‘return’ on the keyboard:
4. Type in a new name and press ‘return’ again:
5. Of course, you can change the flag names at any time: