Microsoft Retires Themes by Copilot in Outlook Starting in Mid-October 2026

Microsoft is retiring Themes by Copilot in Outlook worldwide, with the removal starting in mid-October 2026 and expected to finish by late October 2026, according to the Microsoft 365 Message Center post MC1492954, published on October 9. The change applies to users with a Copilot license on new Outlook for Windows , Outlook for Android, Outlook for iOS, Outlook for Mac, and Outlook on the web. Once the retirement reaches an account, Themes by Copilot is removed from Outlook's settings.