Microsoft 365 for IT Pros September 2026 Release

Monthly Update #135 Now Available for Subscribers to Download

After a busy month, the Microsoft 365 for IT Pros writing team is pleased to announce that the September 2026 update is now available for subscribers to download from Gumroad.com. New PDF and EPUB files are available for the four books in the package:

• Version 135 of Microsoft 365 for IT Pros (2027 edition).
• Version 27 of Automating Microsoft 365 with PowerShell (2027 edition).
• Version 3 of Power Platform for IT Pros (2027 edition).
• Version 3 of Microsoft Purview for IT Pros (2027 edition).

We also updated the paperback edition of Automating Microsoft 365 with PowerShell that’s available on a print-on-demand basis from Amazon.com.

Details of changes made at a chapter level are available in our change log. Our FAQ contains information about how to download updates.

August Developments

Like any month, a batch of new features appear in tenants. Most of the changes are flagged in advance, but some are not. And the devil is always in the detail when it comes to implementation. Here are some of the articles which appeared on Office365ITPros.com in August 2026:

• Microsoft introduced the Invoke-ChangeMeetingOrganizer cmdlet in the Exchange Online PowerShell module to address a longstanding problem which occurs when someone leaves an organization and is the organizer of future meetings (individual events or meeting series). It’s great that Microsoft wants to fix the problem, but the current cmdlet is flawed, especially when it comes to meetings that are linked to online Teams events.
• Also in Teams, a new policy is rolling out to deal with online recording bots which attempt to join meetings.
• The Entra admin center started to display notices to inform tenants when Entra thinks that the tenant doesn’t meet the requirements for premium licenses. Given the need for Entra P1 licenses to cover conditional access policies and other features, it wouldn’t be surprising if many tenants have a licensing deficit. We wrote a PowerShell script to calculate the licensing gap to help inform the conversation.
• Entra also published plans to drop the MemberOf operator for dynamic membership rules in November 2026. That doesn’t sound too serious, but it means that anything which depends on the operator, like dynamic Microsoft 365 groups or dynamic administrative units, will have frozen membership from that point. In turn, this could mean that features like group-based licensing won’t work as expected. Tenants should check if they use the memberOf operator.
• Microsoft 365 Business tenants received a useful bump in mailbox quota from 50 GB to 100 GB. The increase will please many people, but I wonder if Microsoft would have delivered even more value by making archive mailboxes available to all Business tenants.
• Microsoft introduced an interesting ability to use retention policies and labels to archive SharePoint and OneDrive files during their retention period. The feature provides a good way to retain files in lower-cost storage and has the side effect of preventing Copilot from using archived content. Oddly, the UX for the new capability disappeared for a few days, but it’s back now.

These and other changes are covered in the book updates.

Moving Forward

Microsoft 365 continues to evolve and there’s no reason to expect that the rate of change will decline in September 2026. Indeed, some changes, like the campaign to eradicate Exchange Web Services (EWS) from Microsoft 365 is gathering pace and tenants should know by now if they have any applications that need code changes to work before EWS disappears from Microsoft 365.

We’ll keep reviewing what happens so that we can analyze and report the practical implications of change across Microsoft 365 in the books, including topics of interest that will never be included in a book chapter, like the ongoing investigation into why a relatively simple Loop workspace expanded to fill a SharePoint Embedded container occupying over 88 GB of valuable storage.

On to Monthly Update #136

Does time and experience make it easier to generate updated books every month? Well, yes and no. I’d like to think that we improve and understand the process better the more times we go through it, but each month something different shows up to remind us that we’re dealing with software. If it’s not a Word glitch, it might be a bad font export to PDF, or an unexpected issue in EPUB generation. Life continues to be interesting! Enjoy the September 2026 updates.