To manage your flagged email directly in Microsoft To Do, sign in with the same work, school, or personal Microsoft account that you use for email.
Note: This feature is only available if you're using an account that's hosted by Microsoft, such as an Outlook.com, Hotmail.com, or Live.com account. It's also available if you're using an account hosted by Microsoft but using a custom domain.
To see your flagged email tasks, navigate to the list menu, then select Flagged email > Create.
Alternatively, you can turn the list on in Settings.
Once turned on, email flagged in Outlook will appear as tasks in Microsoft To Do. The task's name will be the subject of the flagged message and will include a preview of the email's text in its detail view. To open the original email, select the option to Open in Outlook from the task's detail view.
Items in the flagged email list can be renamed, assigned due dates and reminders, added to My Day, and marked as important.
Note: The flagged email list only shows tasks from messages flagged in the last 30 days. It'll show a maximum of 100 of your most recently flagged messages.
Flagged calendar events won't be converted to tasks in To Do and won't appear in the flagged email list.