Steps to fix the error.
-Close out of the web browser completely and re-open it. Then sign back into your email account.
- Sign out of your email account and sign back in again to re-authenticate with Duo.
- Hit the web browser's "refresh" button, which is usually on the top of the window and usually looks like a curving arrow.
- Clear your web browser's "all time" history, cache and cookies.
- Try accessing your email with a private/incognito window.
- Try using a different web browser.
- Check your inbox and sweep rules along with any filtering you have set up within your settings.
Microsoft Support Article: Inbox rules in Outlook Web App
- Check your recycle bin or deleted items inbox.
- Check your Archive box.
- Check your spam, junk and/or other possible inboxes/folders.
- Check to see if you are blocking email addresses within your settings.
- Add email addresses and domains to your "Safe senders and domain" list within the Junk Email settings.
- Microsoft Support Article: Block or allow (junk email settings)
- Check to see if you accidentally have auto-forwarding set up.
- Search for the emails that you may be missing with the search bar to see if they are ending up in a different folder.
- Check your Internet connection on your device.
- Check for any web browser updates on your device.
- Reinstall web browsers onto your device to ensure that you have the most updated ones.
- Check to see if your computer/device has any pending or important updates to run overall.
- Restart your computer/device.