Microsoft to Block Exchange Online for Outdated EAS
🔒 Microsoft will block mobile devices running outdated email software from connecting to Exchange Online if they use Exchange ActiveSync versions below 16.1, effective March 1, 2026. The change applies to native mobile email apps that rely on EAS and does not affect on-premises Exchange installations or users of Outlook Mobile, which uses a different sync method. Administrators can identify impacted devices with a provided PowerShell query and should coordinate updates with device and app vendors to avoid service disruption.