Exchange Online EWS, Your Time is Almost Up | Microsoft Community Hub

Today’s announcement and the retirement of EWS apply only to Microsoft 365 and Exchange Online (all environments); there are no changes to EWS in Exchange Server. Why is EWS being retired? EWS was built nearly 20 years ago, and while it served the ecosystem well, it no longer aligns with today’s security, scale, or reliability requirements.

https://techcommunity.microsoft.com/blog/exchange/exchange-online-ews-your-time-is-almost-up/4492361