I had this problem once before and have forgotten how I cleared the phone's email of falsely indicating an unread email being present when there isn't one.
I may have had to delete and reinstall the email account but would rather not do so if there's an easier method.
The email account is described by the phone as an Exchange account.
Mark
iPhone 6, Windows 10
If restarting Mail and your Mac did not clear the red badge, create a Smart Mailbox for Unread emails and see if anything shows up there.
It's easier to see if you choose to show the Mailboxes Sidebar.
This is not a Mac. This is the iPhone. I thought this forum is 'using the iPhone'?
If I'm in the wrong forum let me know.
Mark
You are in the right forum. First try a Forced Restart. Hold down the Home and Wake/Sleep buttons at the same time for about 15 seconds until the Apple logo appears. You will not lose anything.
If that does not help you may have to reset the account afterall.
First close your Mail App completely from the app switcher window by double clicking the Home button and swiping up the Mail preview pane up until it disappears from the screen. Then go to Settings > Mail, Contacts, Calendars > locate your email provider and click on the account and swipe to Delete. Then do a forced restart. Hold down the Home and Wake/Sleep buttons at the same time for about 15-20 seconds until the Apple logo appears. Then go back to Settings > Mail… and add the account again.
Thanks for the delete/add email info. I did try the forced restart and will do the remove/add.
Mark
You are welcome. Good luck.
Mail says '1 unread' but there are no unread emails
