To enable background download of emails you need to enable Background App Refresh and Notifications for the Outlook app within the app and iOS Settings. Please note that if you force-quit the Outlook app, background download of emails will stop working.
- Enable/disable Background App Refresh in the iOS settings: Settings > Scroll down to the Outlook app > toggle on/off Background App Refresh.
- Enable/disable Notifications in the iOS settings, and via the Outlook app: Settings > Scroll down to the Outlook app > tap Notifications > toggle on/off Allow Notifications.
- Edit notifications via the Outlook app: Settings > under Mail, tap Notifications > Edit notification preferences per account.
To enable the app badge to update in the background, Background App Refresh and Notifications must be enabled via the Outlook app and iOS settings.