Monthly Update #118 for the Office 365 for IT Pros eBook

The Office 365 for IT Pros writing team is delighted to announce the availability of the April 2025 update (monthly update #118) for the Office 365 for IT Pros eBook. Readers can check the update number of the book on the inside front cover. Details of the update are available in our change log.

The Automating Microsoft 365 with PowerShell eBook is updated for April 2025 too. Its current version is 10.1. The new PDF and EPUB files are available to Office 365 for IT Pros subscribers and those who bought a separate subscription for the PowerShell book.

Subscribers can download the updated files from their Gumroad account or by using the download link in the receipt they received by email following their original purchase. The link in the receipt always accesses the latest files. See our FAQ for more information about how to download updates.

Sending Messages to the Wrong Place

There’s been quite a furore about messages being delivered to the wrong person recently. Leaving the politics aside, the situation is a reminder that the same thing could happen in a Microsoft 365 tenant if a user created an Outlook contact group and included someone who shouldn’t receive sensitive or confidential information in the group members. It’s easy to do because Outlook (Figure 1) doesn’t limit membership to a particular type of recipient. The membership of a personal contact group can include existing contacts, people from the address list (GAL), or new contacts.

Administrators have no idea if people use Outlook contact groups because these objects are stored in user mailboxes. When users add contact groups to messages, Outlook expands the memberships to create individual recipients. Exchange Online only sees the individual recipients.

If a message containing sensitive information are delivered to incorrect recipients, senders can attempt to recall the message. However, the recall feature doesn’t work for external recipients. Once a message leaves the tenant, all control is lost.

Protecting Content

Fortunately, Microsoft 365 tenants licensed for Purview information protection can apply sensitivity labels to email and attachments to prevent unauthorized recipients from reading message content. Chapter 19 of Office 365 for IT Pros includes extensive coverage of the rights-management-based encryption used with sensitivity labels. Essentially, if a recipient has not been granted the right to access protected content, they can’t see it. Protection extends to message attachments too.

It’s always embarrassing when confidential material gets into the wrong hands either deliberately or through a user mistake. Sensitivity labels are integrated into all Outlook and Office applications, but their implementation requires substantial planning and deployment effort, including user education. For instance, will label policies require users to apply a sensitivity label to all email or will the focus of protection be on files (messages with protected attachments inherit protection from the attachments)? There’s lots more to think about, and we hope that chapter 19 helps.

On to Update #119

Only two monthly updates remain for Office 365 for IT Pros (2025 edition). We plan to publish #119 for May 2025 and #120 for June 2025 and then move to the 2026 edition with a tentative publication date of July 1, 2025.

Microsoft is currently pouring massive datacenter and software engineering investment into its AI initiatives. Copilot and agents are the obvious signs of that investment within Microsoft 365. Although costly licenses are required to integrate Microsoft 365 data with Copilot, we’re already seeing the introduction of Pay-as-you-go agents as an alternative payment mechanism. It’s easy to imagine how Microsoft might use similar methods to encourage tenants to adopt AI features within applications more broadly. One thing’s for sure: plenty of change remains to play out within Microsoft 365. Our mission to track, analyze, and document how to manage Microsoft 365 tenants will continue.