October Windows Server updates may disrupt Exchange email. Learn which servers are affected, the symptoms, and Microsoft's registry workaround.

Microsoft released out-of-band Exchange Server security update that fixes a high-severity mailbox access vulnerability (CVE-2026-96940).

Microsoft has confirmed that this month's Windows Server security updates are causing OWA sign-in and mail delivery issues on some Exchange Server systems.

Microsoft confirms October 2026 Windows updates are causing Exchange Server failures and shares a temporary workaround for administrators.

A single email, opened in a browser, is all it takes. Microsoft Exchange servers running Outlook Web Access (OWA) are being actively exploited through a spoofing vulnerability tracked as ...

IT pros may face deadlines after some recent Exchange team announcements regarding Exchange Online. The to-do list for IT pros potentially includes the July 15, 2023 deprecation of the Remote ...

Microsoft is tightening the requirements for Exchange Server 2016 and 2019 in hybrid environments starting the second week of September 2026. Servers that hand over emails to Exchange Online via an on ...

Exchange servers go down after Windows Server’s October updates. Microsoft is investigating the issue.

Microsoft patches CVE-2026-96940, which lets authenticated attackers read other users' Exchange mailboxes within the same organization.

“To address [the problem of persistently vulnerable Exchange servers that cannot be trusted], we are enabling a transport-based enforcement system in Exchange Online that has three primary functions: ...