Dear colleagues, 

We want to inform you about a change coming to Microsoft Outlook for Mac that may affect your experience and workflows. 

What’s Changing? 

Starting mid-August 2025, Microsoft will retire the admin preference that allows switching back to Legacy Outlook on Mac.  

What does this mean? 

• • The New Outlook will become the default experience for all users in the Current Channel (version 16.100 and later) on macOS. 

• • By mid-October 2025 (version 16.102 and later), users will no longer be able to switch back to Legacy Outlook on macOS. 

• • All macOS users will transition to New Outlook, which is built on Microsoft’s modern sync technology.  

Useful resources: 

• • Fixes or workarounds for recent issues in Outlook for Mac (June 2025) 

• • If you have any questions or concerns, please contact your local IT support desk. 

Kind regards,   

Enterprise Applications & Solutions Integration (EASI) 

Information Technology Services, University of Toronto