Most RecentMost ViewedMost LikesLimiting Onmicrosoft Domain Usage for Sending Emails We are announcing that all Exchange Online customers who send external email should start switching to custom (aka vanity) domain names. No Exchange Server Security Updates for January 2026 We are not releasing any Exchange Server Security Updates for January 2026. Released: December 2025 Exchange Server Security Updates We have released Security Updates for Exchange Server SE. Exchange Server 2019 and 2016 ESU updates only. Released: October 2025 Exchange Server Security Updates We have released Security Updates for Exchange Server SE, Exchange Server 2019 and Exchange Server 2016. Active Directory schema extension issue if you use a Windows Server 2025 schema master role We wanted to let you know of an Active Directory replication issue you might run into if you use Windows Server 2025 schema master role. No Exchange Server Security Updates for November 2025 We are not releasing any Exchange Server Security Updates for November 2025 Why “in-place upgrade” from Exchange 2019 to Exchange SE is low risk We wanted to share information on why we view the "in-place upgrade" to Exchange SE (when available) as a "low risk" operation. Dedicated Hybrid App: temporary enforcements, new HCW and possible hybrid functionality disruptions We are announcing enforcements to move customers along to using the dedicated hybrid app. Exchange Online ActiveSync Certificate-based Authentication endpoint changes We wanted to let you know about Exchange Online ActiveSync Certificate-based Authentication endpoint changes. Released: August 2025 Exchange Server Security Updates We have released Security Updates for Exchange Server SE, Exchange Server 2019 and Exchange Server 2016.
