Outlook Version Management in Microsoft 365 – Why You Should Care

Author Stefan Fried

In today’s SaaS-driven world, many organizations are unaware that dozens of different versions of the Outlook client are running in their environment—and that could be a bigger problem than you think.

Microsoft controls the update process, promising to keep everyone up to date. But are they really delivering on that promise? IT administrators might argue that they shouldn’t have to worry about software updates for SaaS apps like Microsoft 365. After all, the whole point of SaaS is to minimize the time and effort needed to support functionality while ensuring users always have access to the latest features.

But here’s the catch: in the pre-SaaS era, version management was a challenge, but at least organizations had control and visibility. Today, with Microsoft 365, version management is largely out of sight—and out of mind. If you don’t know whether your users are on the latest version, how can you troubleshoot issues or ensure they’re benefiting from new features? And with Microsoft rolling out updates in phases, it’s even harder to know when your users will get access to those new capabilities.

So, how does Microsoft’s update process for Outlook really work? And what should IT administrators know to ensure their users are getting the most out of the latest features? Let’s dive in.

Microsoft 365 Apps Deployment for the New Outlook Client

The new Outlook client is part of the Microsoft 365 Apps suite, which can be managed and deployed automatically to your users. Through either the?Targeted?or?Standard Release ring, you can decide whether users should receive the latest preview features as soon as they’re available or stick to the standard release once it’s updated.

In general, updates to Outlook are pushed regularly and cause few issues. But “in general” doesn’t mean “always.” So, how can you stay on top of what’s new and ensure your users are benefiting from the latest updates?

How Do You Know What’s New in Outlook?

Microsoft posts release notes for Microsoft 365 apps, including Outlook, on it’s M365 Release notes for Current Channel page. These build release notes provide an aggregated view and in general don’t have a lot of details. For certain apps like OneDrive and Teams, additional pages are available with specific version information but for Outlook, it’s mostly just the M365 build page itself.

M365 builds are listed with their release date. However, this doesn’t mean all users will get all features mentioned right away, or even at the same time. Microsoft explicitly states on its release notes page that feature rollouts are phased, and there’s no guarantee all users will receive updates simultaneously.

Additionally, the release notes don’t list a specific version number for the Outlook client with each feature—only the general build number. This makes it nearly impossible to correlate new features back to the specific Outlook client version in which they were released.

Example: The latest build release notes that references changes to Outlook might be?Build 2412, released on January 7, 2025. But this doesn’t align with the Outlook version number you see in the app’s settings (e.g.,?1.2025.117.600). This lack of clarity can make it difficult to track which features are available in which versions.

Another way to learn about upcoming changes is through the?Message Center, where Microsoft posts information about new features. But again, there’s no indication of which Outlook version is required to access a specific feature.

Why You Should Care About Version Management

You might be thinking:?“But Stefan, this isn’t important because every user should always have the same, latest version. Everything I see on Microsoft’s pages will soon be available to my users!”

My response? That’s true—if?updates work as intended. But what if they don’t? What if some users aren’t receiving updates due to technical issues? Or what if Microsoft’s phased rollout means some users are left behind temporarily?

It can be frustrating to train users on a new feature, only to discover they don’t have access to it yet. Even worse, you might not know whether the issue is due to a delayed rollout or a failed update. And yes, that happens more often than you’d think.

So, How Many Versions Are in an Average Environment?

Let’s look at an example. for two organizations, we analyzed the different Outlook client versions used over the past seven days. The result??Nearly 90 different versions?were in use at the time of checking at the large organization and 36 different Outlook client versions at the mid-sized one.

That sounds like a lot—and it is! While many of these versions may only have minor differences in terms of improvements and bug fixes, some discrepancies are significant. For instance, there was over three years difference between the release of the oldest version in use at these organizations and the release of the latest version. Users on the older version missed out on multiple updates including perhaps critical security patches and new features. That’s a potential risk no organization should ignore.

Why Version Visibility Matters

Knowing which users are on older Outlook versions—and which versions are deployed across your organization—is crucial for:

1. Security: Ensuring users have the latest security patches.
2. User Satisfaction: Guaranteeing users can access new features and improvements.
3. Effective Communication: Enabling you to communicate changes and train users effectively.

Would having version visibility solve all your problems? Not entirely, as Microsoft still doesn’t provide comprehensive release notes for the Outlook client. But it would give you a clearer picture of what your users likely have access to and whether updates are functioning as they should.

OfficeExpert TrueDEM Provides the Insight You Need

This is why?panagenda?is introducing the?Outlook Versions Report?as part of its M365 monitoring suite. With this tool, you’ll be able to:

• See which Outlook versions were actively used in the last seven days. Both for the Outlook app as well as the Classic Outlook version that many users still use.
• Identify users or configurations that require attention.
• Troubleshoot why some users aren’t receiving updates1.
• Encourage and train users to switch from the Classic Outlook client to the New Outlook client.

Summary

In short, while Microsoft 365’s SaaS model simplifies many aspects of IT management, it also introduces new challenges—especially when it comes to version control and update visibility. With dozens of Outlook versions potentially running in your environment, staying informed is critical to maintaining security, user satisfaction, and operational efficiency.

By leveraging tools like?OfficeExpert TrueDEM, you can gain the insights needed to ensure your users are benefiting from the latest Outlook updates—and that your organization isn’t left vulnerable to outdated software.

1 If you’re struggling with non-updating clients, you might find our previous blog post on?solving Teams version update problems helpful. Many of the issues with Teams updates are similar to those with Outlook.