This is the text of the upstream bug: EWS accounts (Outlook365) are unusable in 24.02 beta - after authenticating, the mail is synced once, and then the account is disconnected and one needs to go to the accounts settings and re-authenticate every time. Another system with 23.08 works fine, so this is not a server side issue. --- Sometimes the connection last for a while, but it eventually always disconnects, and it does not remember the credentials between logins. There are a few patches in the upstream bug but they don't really work very well (or at all).
What's the status with 24.02.1?
(In reply to Andreas Sturmlechner from comment #1) > What's the status with 24.02.1? It looks a bit better, but not perfect yet. :-/ Basic functionality works, but it still outputs a lot of "org.kde.pim.ews.client: Failed to process EWS request:" in the journal
Thanks, please follow up with upstream on that.