M365 Changelog: Update to Microsoft 365 and Outlook for Windows connectivity

MC288472 – 30-day/Final Reminder (MC229143 – DEC ’20 and MC274503 – July ’21): To ensure that Microsoft meets performance expectations, they are updating the supported versions of Outlook for Windows that can connect to Microsoft 365 services.

Starting November 1, 2021, the following versions of Outlook for Windows, as part of Office and Microsoft 365 Apps, will not be able to connect with Office 365 and Microsoft 365 services.

Office and Microsoft 365 Apps	Outlook for Windows Version
Office 2013	15.0.4970.9999 and older
Office 2016	16.0.4599.9999 and older
Microsoft 365 Apps for enterprise (formerly Office 365 ProPlus)	1705 and older
Microsoft 365 Apps for business (formerly Office 365 Business)	1705 and older

Key Points:

• Major: Retirement
• Timing: Beginning November 1, 2021 and will be complete by mid-May 2022.
• Action: Ensure Outlook for Windows client are updated accordingly

How this will affect your organization:

Versions that are newer than minimum version requirements listed above, but are not the currently supported version, may experience connectivity issues.

To see a list of the currently supported versions, visit Update history for Microsoft 365 Apps (listed by date) (for Microsoft 365 Apps) or Latest updates for versions of Office that use Windows Installer (MSI) (see “Latest Public Update” for Office 2013 and 2016).

Supported versions of Outlook for Windows in Office and Microsoft 365 will continue to connect to Microsoft 365 services as expected.

What you need to do to prepare:

Microsoft recommends that all users upgrade to the supported versions of Office and Microsoft 365 Apps.