Mail

carolagate,

In the left side column, is Favorites listed at the top of it? If so, hover your mouse next to the word Favorites and click the plus sign. Then click the dropdown box to the right of Mailbox to Add in the window that appears. Choose Flagged and OK. It should then appear in the left side column. It should also have a small arrow in front of it that you can click on to show the list of the different color flags.

Let us know how this goes.

Regards.

Hello carolagate,

Thank you for using Apple Support Communities!

We understand from your post that you would like to view all your flagged email by color. This article has information on how you can view your flagged emails in macOS Big Sur:

Flag emails in Mail on Mac - Apple Support

Best Regards.

That worked! -- Not sure why it was deselected, but glad to have them back.

Worked for me too!