How to unflag 5,000 emails at once

It depends a little on which device you are using. Here is an AI overview...

AI Overview

To unflag many emails at once in Apple Mail, go to the "Flagged" mailbox, press Command + A on a Mac to select all messages, then right-click and choose "Clear Flag". On iPhone/iPad, go to the "Flagged" mailbox, tap "Edit," then "Select All," and tap "Mark" followed by "Unflag". 

Steps for Mac (macOS):

1. Open Mail and click the Flagged mailbox in the sidebar.
2. Click on any message in the list, then press Command + A to select all flagged messages.
3. Right-click (or Control-click) on the selected messages.
4. Select Flag from the menu and choose Clear Flag. 

Steps for iPhone/iPad (iOS):

1. Open the Mail app and ensure you are in the Flagged mailbox.
2. Tap Edit in the top right corner.
3. Tap Select All in the top left corner.
4. Tap Mark in the bottom left corner.
5. Select Unflag to remove all flags at once. 

Alternative Methods:

• Mac: Use Shift + Click to select a range of emails or Command + Click to select individual emails, then right-click to clear flags.
• Web: Log into iCloud.com in a browser to use the same "Select All" method if necessary. 

I have the same IOS version on my iPad. Once you see "Select" if you tap on that, the Select All option appears.