For classic Outlook on Windows, check these items in order:
- In Outlook, go to File > Options > Mail.
- Under Message arrival, make sure Display a Desktop Alert is enabled.
- In the same section, make sure Show an envelope icon in the taskbar is enabled if the missing “badge” is the taskbar mail indicator.
If alerts still do not appear:
- Desktop Alerts do not appear during the initial synchronization of an email account.
- Desktop Alerts also do not appear when a message rule moves a new message out of the default account Inbox.
If using new Outlook instead of classic Outlook:
- Open Outlook.
- Go to View > View Settings > General > Notifications.
- Under Notify me about, turn on Mail.
If notifications are enabled in Outlook but still missing, check Windows:
- Open Start > Settings > System > Notifications.
- Make sure Get notifications from apps and other senders is On.
- Make sure Do not disturb is Off.
- Make sure Outlook notifications are allowed in the app list.
- Open Start > Settings > System > Focus and stop any active focus session.
- Open Start > Settings > System > Power & battery and make sure Battery Saver is off.
If using Teams, make sure the Teams status is not set to Do not disturb.