We want to inform our users and organizations about an important upcoming change regarding Exchange ActiveSync (EAS) device connectivity to Exchange Online. Starting March 1, 2026, devices running ActiveSync versions lower than 16.1 will no longer be able to connect to our services. EAS 16.1 was released as a part of Exchange Server and Exchange Online in June 2016.
This decision comes after extensive collaboration with multiple licensed device and application vendors to ensure a smooth transition for as many users as possible. If users and organizations keep their devices and applications updated to the latest supported versions, there should be minimal disruption in service. We encourage everyone to verify their devices and applications are up to date before the change takes effect.
An admin can quickly get a report of the devices and apps using versions of ActiveSync below version 16.1 by using PowerShell. Here’s an example:
Get-MobileDevice | Where-Object {($_.ClientType -eq 'EAS' -or $_.ClientType -match 'ActiveSync') -and $_.ClientVersion -and ([version]$_.ClientVersion -lt [version]'16.1')} | Sort-Object UserDisplayName | Select-Object UserDisplayName, UserPrincipalName, DeviceId, DeviceModel
If you have any questions or need assistance with updating your devices, please reach out to your device or application vendor.
Please note that this announcement applies only to Exchange Online (not Exchange Server) and only to mobile devices using native email apps. Apps like iOS Mail app (adopted EAS 16.1 with iOS 10), the Gmail app or the Samsung mail app (both of which are working on updating their apps now, so just keep them up to date and they will start using 16.1 soon) when accessing mailboxes in Exchange Online. Devices that use Outlook Mobile to connect to Exchange Online do not use the EAS protocol and are not impacted.
Thank you for helping us maintain a secure and reliable environment for all users.
The Exchange Team
