Microsoft is rolling out its biggest M365 platform refresh in years throughout Q1 2026. From a forced migration to New Outlook to larger Teams channels and Defender security in lower licence tiers — here is everything every IT administrator needs to know.
Microsoft is implementing a series of significant changes across the Microsoft 365 platform in the first quarter of 2026. Some changes are immediately visible to end users, while others primarily affect IT administrators and procurement teams. This article outlines the most important updates.
The most visible change is the phased mandatory transition from Classic Outlook to New Outlook for Windows. Microsoft is automatically switching all users to New Outlook. The new version uses a web-based rendering engine rather than the legacy COM architecture, making it functionally equivalent to Outlook on the web.
For end users, this means a familiar but refreshed interface. For IT administrators, the biggest challenge is compatibility with existing add-ins and macros built on the classic COM architecture. A timely inventory of dependencies is essential to prevent disruption.
Microsoft is significantly raising the maximum limits for private channels in Teams. Teams now supports up to 1,000 channels per team and 5,000 members per channel — a substantial increase from the previous limits of 30 and 250 respectively. This makes Teams better suited for large organisations with complex collaboration and communication structures.
At the same time, Planner in Teams receives an update with task conversations via @mentions, rich text and customisable templates. IT administrators can pre-configure templates based on JSON-based plan layouts, simplifying standardisation of project workflows across the organisation.
A significant change for security administrators: Microsoft is adding Defender for Office 365 Plan 1 features to E3 and Microsoft 365 E3 licences. Safe Attachments and Safe Links — protecting against phishing and malware in email and collaboration tools — were previously only available as an add-on or in higher bundles.
In addition, URL scanning is being added to E1, Business Basic and Business Standard licences. For small and medium-sized businesses, this represents a concrete security improvement at no additional licence cost.
Microsoft has announced pricing changes taking effect from 1 July 2026. Organisations renewing contracts or purchasing new licences should factor these changes into their budget planning. Contact your Microsoft partner for an up-to-date licence overview.
From 9 March 2026, Microsoft Lens has been retired as a standalone app. The functionality is not lost: scanning and OCR are integrated into the Microsoft 365 mobile app and OneDrive. Organisations that have included Microsoft Lens in workflows or documentation should update these accordingly.
The combination of the Outlook migration, pricing changes and expanded Defender functionality makes Q1–Q2 2026 a busy period for Microsoft 365 administrators. Prioritise: (1) Outlook add-in inventory, (2) licence review in light of new bundles, and (3) activation of the new Defender features. Zarioh Digital Solutions supports you with all three.
