Announcing retirement of the legacy mail flow rules UX in the classic Exchange admin center
The retirement process of the mail flow rules user experience in the classic Exchange admin center begins at the end of November. The legacy UX is no longer the default page in the new EAC and is available only in the classic EAC and only until it is retired. This is part of our ongoing transition to move away from the classic EAC for mail flow management, and it is a continuation of our migration to the new EAC (admin.exchange.microsoft.com).
The new mail flow rules UX is now the default experience in the new EAC. Please begin to familiarize yourself with the new experience. Although the UX has been modernized, you will find that most of the workflows have remained the same to ensure a smooth transition.