Cypht supports IMAP/SMTP, JMAP and EWS (in upcoming Cypht 2.50) which reinforces its positioning as a great Open Source webmail aggregator.
However, there are changes ahead for EWS:
"(...) on October 1, 2026, we will start blocking EWS requests to Exchange Online. (...) we strongly suggest migrating to Microsoft Graph to access Exchange Online data (..). 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. EWS will continue to be fully supported for Exchange on-premise mailboxes."
Source: https://techcommunity.microsoft.com/blog/exchange/retirement-of-exchange-web-services-in-exchange-online/3924440
Cypht users can continue to access Exchange Online via IMAP:
https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/pop3-and-imap4/pop3-and-imap4
https://www.cypht.org/cypht-enable-outlook-and-office365-oauth/