Learn about Exchange Server, hybrid environments, and M365 security gaps with Microsoft MVP Thomas Stensitzki. Essential insights for cloud architects.

Exchange Server Health Check with PowerShell: run Microsoft's Health Checker script, work through 11 manual checks, and see what out-of-support really means.

On September 2026 Patch Tuesday Microsoft delivered a record-breaking number of patches, including for two bugs exploited as zero-days.

Microsoft is beginning to sever outdated on-premises Exchange servers from cloud mail more sternly. From the second week of September 2026, Exchange Online will start to restrict, and thereafter block, messages from Exchange Server 2016 and 2019 unless the servers have been updated at least to the final public level of October 2025. For companies that have deferred updating their corporate mail for years, the warnings have, in effect, come to an end.

Guía completa sobre el nuevo bloqueo de Microsoft a Exchange 2016/2019 desactualizados. Fechas, requisitos y soluciones para admins.

August 2026 Patch Tuesday delivered 398 resolved CVEs, highlighting the ongoing Patch Apocalypse and the pressure created by rapid AI-driven vulnerability discovery. SharePoint, Exchange Server, Azure Arc, Microsoft Defender, and Chrome all featured high-risk issues, including actively exploited and publicly disclosed flaws that demand fast patching and layered network defenses. #SharePoint #ExchangeServer #AzureArc #MicrosoftDefender #Chrome #ShieldBreak #CVE-2026-55040 #CVE-2026-63520 #CVE-2026-62911 #CVE-2026-69414 #CVE-2026-85046

TL;DR Security researchers publicly disclosed technical details for an Exchange Server pre-auth RCE flaw tracked as CVE-2026-62911. The critical vulnerability allows unauthenticated attackers on local networks to achieve remote code execution as SYSTEM. Administrators must apply official Microsoft patches immediately to safeguard exposed mail servers. Why It Matters Security researcher Orange Tsai demonstrated the zero-day attack at Pwn2Own Berlin 2026…

Microsoft finds itself unable to release the inaugural cumulative update for Exchange Server Subscription Edition according to its original schedule. Initially anticipated by the close of the first half of 2026, the Exchange SE CU1 release was subsequently deferred to the latter half of the year; now, the corporation has refrained from providing any definitive timeline altogether. This postponement stems from an overwhelming burden placed upon developers, driven by a surge in security vulnerabilities uncovered, in part, through novel artificial intelligence instruments.

Exchange Server SE CU1 is taking longer than expected, but Microsoft says the update is still coming as IT admins await a release date.

Microsoft has retired a long-standing Exchange Server feature with its latest security update, but another issue could still affect hybrid deployments.