Customers who opt-in to the early version of the new Outlook on the web will see a newly redesigned Tasks experience, powered by Microsoft To-Do. They will be gradually rolling this out to Targeted Release customers in March, and the rollout will follow the general release timeline of the new Outlook on the web.
This rollout is excluded from Office 365 subscriptions in GCC.
If you white-list or block domains that can be accessed by your users – Please note that the new Tasks experience powered by To-Do uses the “to-do.office.com” domain, so you might wish to whitelist domains accordingly for your users to be able to use the new Tasks experience.
If you don’t white-list/block any domains, you don’t need to do anything.