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

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

Microsoft has acknowledged that the October 2026 Windows Server updates may be destabilizing Exchange Server. The problems are related to this list of Windows Server updates (see here) and Microsoft ...

Microsoft is working to resolve an ongoing Exchange Online outage that is delaying email sent to and received from external domains. The company first acknowledged this incident (tracked under ...