Apple Mail 14.0

Hi Kathie Hagwell,

Welcome to Apple Support Communities. We understand you're unable to flag emails in the Mail app of your Mac. We'll be happy to help.

In the Mail app, do you have, column layout turned on? To verify that, please open the Mail app on your Mac and navigate to the menu bar by selecting, View > Use Column Layout. If so, you can move the cursor to either, "From" or "Subject" in the column label and press "control" + Click/Right Click > select "Flags."

If needed, here's more information about column layout in the Mail app: Use column layout in Mail on Mac

Now if, "Use Column Layout" is not turned on and you're referring to not seeing the flag emails in the sidebar of the Mail app, let's ensure that the sidebar is not hidden. To verify that the sidebar is displayed, please press Shift-Command-M.

Please let us know if that helps.

Kind regards.

Kathie Hagwell,

That's wonderful to hear! Thanks for getting back to us and for providing that update. Have a great rest of your day.

Cheers!