Small Business
Three Microsoft Deadlines This November: What Changed in October, What to Decide Now
Exchange Online started blocking an older email API this fall, Windows 10 Extended Security Updates just entered a pricier second year, and one specific Windows 11 version runs out of support this week. None of these is a security incident, but each one needs a decision this November before it becomes an outage.
Direct answer: three Microsoft deadlines that moved in October 2026 all need a decision this November. Exchange Online started blocking an older email API that quietly backs a surprising number of business integrations. Windows 10 devices still enrolled in Extended Security Updates just moved into a pricier second year. And any Windows 11 Enterprise or Education PC still running version 23H2 loses security updates this week unless it is updated. None of these is a security incident. All three are deadlines a business can still act on before they cause one.
Exchange Online Is Starting to Block an Older Email API
What changed: Microsoft's Exchange Team confirmed that, on or soon after October 1, 2026, Exchange Online began changing a tenant setting called EWSEnabled from its default of "not set" to "blocked" for any tenant that never explicitly configured it. EWS, short for Exchange Web Services, is an older API that predates Microsoft Graph, and Microsoft says there will be no exceptions once EWS is fully and permanently shut off on April 1, 2027.
Why it matters: Nobody in most small businesses thinks about EWS day to day, because it is not something end users touch directly. It is the thing a backup tool, a CRM sync connector, or an older Outlook add-in uses in the background to read or write mailbox data. When Microsoft blocks it for a tenant that never explicitly addressed the setting, those integrations can fail quietly: a backup job stops completing, or a CRM sync just stops updating, often with no error message that points back to the actual cause.
What to do in November: In the Microsoft 365 admin center, pull the EWS usage report under Reports, which lists which applications in your tenant are still calling EWS. Keeping any of those integrations running past the transition takes two things together, not one: EWSEnabled has to be set to True (Microsoft allows a temporary re-enable if something has already broken), and that application's AppID has to be on the allow list, since once EWSEnabled is True only allow-listed apps get through. Neither of those is the actual fix, only a bridge; the fix is migrating each app off EWS to Microsoft Graph before April 2027, when the shutdown becomes permanent with no exceptions.
Windows 10 Extended Security Updates Just Entered a Pricier Second Year
What changed: Commercial Windows 10 devices enrolled in Extended Security Updates (ESU) are now in Year Two of the program. Microsoft's own ESU program page sets Year One commercial pricing at $61 per device through the Volume Licensing Program, and states plainly that the price doubles every consecutive year, for a maximum of three years. By that stated rule, Year Two works out to roughly $122 per device, and Year Three to roughly $244, for a program that only runs three years total before Windows 10 devices lose security updates for good regardless of payment.
Why it matters: ESU was always meant to be a bridge, not a destination, and the per-device price for that bridge just roughly doubled. A business that enrolled a batch of older machines last year to buy time is now paying meaningfully more for the same coverage, with one more price doubling still ahead before the program ends entirely.
What to do in November: Get an exact device count still enrolled in or eligible for ESU, and confirm your actual Year Two invoice amount with Microsoft or your licensing partner rather than assuming a number from general reporting, since the final price depends on your specific licensing agreement. Then decide, machine by machine, whether paying for another year still makes sense versus replacing or upgrading the hardware before the Year Three price applies.
Windows 11 Enterprise and Education Version 23H2 Runs Out of Support This Week
What changed: Microsoft's own product lifecycle page lists Windows 11 Enterprise and Education, version 23H2, as reaching end of servicing on November 11, 2026. After that date, a device still running 23H2 stops receiving security updates entirely, even though the Windows 11 Enterprise and Education product line itself remains fully supported on a newer version.
Why it matters: This one is easy to miss because it is not the headline "Windows 11 is ending" story; it is one specific feature-update version quietly falling out of support while the overall operating system keeps going. A business running deferred updates or a slow rollout schedule can easily have machines still sitting on 23H2 without anyone having flagged it.
What to do in November: Check which devices in your fleet are still on version 23H2, through Intune, Windows Update for Business reporting, or even Settings > Windows Update > About on a sample of machines. Any device still on 23H2 needs to move to a newer supported version, 24H2, 25H2, or 26H2, this month, not on whatever cadence it would normally update.
How Cyber One Solutions Helps
Our Managed Cloud services include ongoing Microsoft 365 and Exchange Online administration, so an EWS dependency check and any needed Graph API migration get handled as routine tenant management rather than discovered after an integration breaks. For the Windows 10 ESU decision and the Windows 11 version-currency check, our Managed IT services cover endpoint inventory, patch management, and feature-update deployment across your fleet, which is also how we help clients decide device by device whether another year of ESU or a hardware refresh makes more sense. If you want a structured way to evaluate what a managed IT provider should actually be handling for you, day to day, our Managed IT buyers guide walks through the scorecard. If any of the three deadlines above apply to your environment, contact us and we will help you work through it before it becomes an outage.
Frequently Asked Questions
Do we need to do anything about EWS if we do not recognize the term?
Check anyway. EWS is not something end users interact with directly, so "we do not use that" is often wrong; it is usually a backup tool, CRM connector, or an older add-in using it quietly in the background. The Microsoft 365 admin center's EWS usage report is the fastest way to find out whether anything in your tenant depends on it before Microsoft's block reaches you.
Does the Windows 10 ESU price increase apply even if we only enrolled partway through Year One?
The ESU program does not sell partial years, and Microsoft's program terms treat enrollment as cumulative: joining late still means paying for the years you missed. Confirm your specific enrollment date and current invoice with Microsoft or your licensing partner, since the exact billing can vary by how and when you joined.
Is the Windows 11 23H2 deadline the same thing as "Windows 11 support ending" that we have already heard about?
No. This is specific to one feature-update version, 23H2, for the Enterprise and Education editions. Windows 11 Enterprise and Education as a product line remains fully supported; only devices still running the specific 23H2 release lose security updates after November 11, 2026, and only until they are updated to a newer supported version.