Super slow connections to self-hosted (NTLM) exchange server...
I've massive problems with evolution-ews since 3.5x.
The theoretical authentication/connection to NON-365 exchange server at exchange2019.ionos.de seems working as in 3.42.x.
But synchronization then is terrible. It takes hours to synchronize email and calendar - while it takes seconds/minutes for the same job on 3.42.x. Contacts will never get synchronized. The evolution front-end is showing endless IO time-out errors.
I'm getting this problems on OpenSuse. Since Leap ~15.1, up to Leap 15.5 everything was perfect. But on 15.6-RC and Tumbleweed evolution-ews isn't usable anymore with the exchange2019.ionos.de server.
Yeah, I'm not supplying you right now with a perfect issues description. Please, give me some advice what to do, to supply you with more/better information's. Anyway I'll later pick another distribution to verify that the problem isn't just OpenSuse related. I also could sponsor you for a while an account at exchange2019.ionos.de.
I'm actually getting around the issue with using a self made flatpak based on evolution 3.42.5 - this is working like a charm on Tumbleweed and 15.6-RC.
edit:
I need to add, that the "self-hosted" in the issues subject could be misleading. The "exchange2019.ionos.de" server is not driven by Microsoft or part of their 356-stuff - but it's the biggest exchange-instance in Germany not driven by Microsoft.