With the last update of To-Do across platforms we have enabled the option to see flagged emails from Outlook as Tasks in Microsoft To-Do. Simply flag an email in Outlook to create a task from it in To-Do.
You can enable this feature in Microsoft To-Do from within the App Settings.
To get the latest version of To-Do please go to https://products.office.com/en-us/microsoft-to-do-list-app
An error occurred while saving the commentJP Clement commented
Feature in Mac OS opens Outlook Web, not the local Outlook client app. Useless now but would be great to have! Already suggested several times in the comment section but no upvote option.