Hi.
Installed Kubuntu 20.04 LTS few days ago, then installed Kontact manually from Discover, as it's not default anymore. Tried to set up my business email (Exchange) in KMail client, receiving messages works normally, but sending messages gives me an error "kmail failed to get d-bus interface of resource akonadi_ewsmta_resource_0". Previously I had Kubuntu 18.04 and Kubuntu 19.10 - in those KMail worked perfectly. Has anyone else experienced this bug? Are there any advices on how to overcome this? Currently I have to use thunderbird, which is fine, but I like KMail functionality and looks much more, so I would appreciate any help.

Solved by complete reinstalling Kubuntu 20.04.
Before that tried to reinstall Kontact, but that did not help.