Office 2016 & 2019 won’t be supported for connecting to Microsoft 365 services, including Exchange Online, starting Oct 2023 as documented here:
- Office versions and connectivity to Microsoft 365 services
https://docs.microsoft.com/en-us/deployoffice/endofsupport/microsoft-365-services-connectivity - Windows Configuration Support Matrix &
Connectivity to Microsoft 365 Services Matrix
https://query.prod.cms.rt.microsoft.com/cms/api/am/binary/RE2OqRI
This means, as of this writing, your organization has a little more than 1 year to migrate off of “Office 2016/2019” and onto “Microsoft 365 apps” to continue to access Exchange Online (Outlook), OneDrive for Business (Word/Excel/PowerPoint) & SharePoint Online from the desktop office suite.
MOVING TO MICROSOFT 365 APPS
Learn how to move on to Microsoft 365 apps (formerly known as “Office 365 Pro Plus”, a.k.a. the version of the Microsoft Office suite that comes with Office 365 E3+) today.
- Microsoft Mechanics: Office and Microsoft 365 Apps Deployment & Update Management 2022
https://youtu.be/hP9VWX8cI3Q