Table of Contents
Summary
- Devices using Exchange ActiveSync versions lower than 16.1 will lose connectivity to Exchange Online.
- Organizations using native email apps may be affected; Outlook Mobile will remain unaffected.
- Admins can run a PowerShell command to identify devices using outdated EAS versions.
- Users should be informed to update their devices and applications to meet the new requirements.
- This change applies exclusively to Exchange Online, not to Exchange Server.
Admin Impact: High
User Impact: High
Release Start: 01 Mar 2026
Release End: 01 Mar 2026
Services: Exchange
Category: Plan for change
Tags: User Adoption, Admin Action, Retirement
History
12/15/2025 Item Added to Message Center
Microsoft Message
Updated December 16, 2025: We have updated the PowerShell example. Thank you for your patience.
Exchange Online ActiveSync Device Support Update
We’re making a change to improve security and reliability in Exchange Online. Starting March 1, 2026, devices using Exchange ActiveSync (EAS) versions lower than 16.1 will no longer be able to connect to Exchange Online. EAS 16.1 was introduced in June 2016 and provides enhanced compatibility and security.
When this will happen
This change begins taking effect on March 1, 2026.
How this affects your organization
Who is affected: Organizations using mobile devices with native email apps to access Exchange Online mailboxes via EAS protocol. Apple devices added support for EAS 16.1 in iOS 10 and are unlikely to be affected. The Gmail app and Samsung Mail will have updated versions available before the deadline. For other apps you should contact your device or application vendor if they are using EAS versions lower than 16.1.
What will happen:
- Devices running EAS versions lower than 16.1 will no longer connect to Exchange Online.
- Devices using Outlook Mobile are not impacted because they do not use EAS.
- This change applies only to Exchange Online, not Exchange Server.
What you can do to prepare
- Verify that all mobile devices and applications are updated to EAS version 16.1 or higher before March 1, 2026.
- Admins can generate a report of devices using older EAS versions with the following PowerShell command:
Get-MobileDevice -ResultSize Unlimited | Where-Object {($_.ClientType -eq 'EAS' -or $_.ClientType -match 'ActiveSync') -and $_.ClientVersion -and (
version
$_.ClientVersion -lt
version
'16.1')} | Sort-Object UserDisplayName | Select-Object UserDisplayName, Identity, DeviceId, DeviceModel | Format-List
- Communicate this change to your helpdesk and end users and ask them to update if possible.
- Update internal documentation as needed.
- For assistance, contact your device or application vendor.
- Learn more: Exchange ActiveSync in Exchange Online
Compliance considerations
No compliance considerations identified, review as appropriate for your organization.