We’re seeing positive results for service stability and increased capacity as a result of our latest traffic optimization actions. We're implementing these actions more broadly across affected regions as we seek to attain persistent recovery. A more comprehensive update can be found at MO1550821 in the Microsoft 365 admin center, as well as https://t.co/pYdahqxDv3 if the admin center is not available to you.
We're investigating reports of users experiencing issues accessing Exchange Online mailboxes through multiple connection methods in the Americas. More details can be found in the Microsoft 365 admin center under EX1550543.