Microsoft delays enterprise Outlook switchover to 2027

Microsoft delays enterprise Outlook switchover to 2027

By Craig Hale
Publication Date: 2026-03-09 17:10:00


  • New Outlook opt-out phase pushed from April 2026 to March 2027
  • Microsoft wants to “continue delivering key features and improvements”
  • Companies also given “the time they need to prepare” for the switch

Just weeks ahead of its previously-set April 2026 deadline, Microsoft has announced it will be delaying the opt-out phase for enterprises to upgrade to the new Outlook by around one year to March 2027.

The opt-out phase will see the new version of the email provider become default by experience, but companies can choose to opt out during this temporary phase as they grapple with rolling out the update more effectively.