Effective March 1, 2026, it will no longer be possible to connect devices using Exchange ActiveSync (EAS) versions lower than 16.1 to Exchange Online. Devices and applications using older implementations of this protocol will lose the ability to synchronize emails, calendars, and contacts.
This change primarily affects certain mobile email applications, such as Gmail, Samsung Mail, or BlueMail, as well as client add-ons and synchronization tools (e.g., TBSync) that utilize outdated versions of the EAS protocol to communicate with Exchange mailboxes.
EAS version 16.1 was released back in 2016 and represents the minimum supported level for security and compatibility. The aim of this change is to enhance user data protection and unify support for modern clients and technologies.
We therefore recommend verifying your applications and devices in a timely manner and ensuring they are updated or migrated to supported email clients to avoid any interruption in mail access after the specified date.