This is a wish or a bug, depending on how you would like to see it. I have a caldav calendar source which I am using for group scheduling (Sogo). When I receive invitations to events I get notification mails (or not, depending on the client and its settings used by the event creator). Korganizer does however not show these events (and I did not find a setting to make it show them). Thus, the two options I have to confirm my participation in the event are * Go to the webpage of Sogo and confirm the event there * Confirm the event using the mail client. This will also send a mail to the creator of the event (at least in kmail I do not know how to suppress that). It would be more convenient if korganizer would optionally show the unconfirmed events (perhaps greyed out, in a different color or with less opacity). That should allow to open the event from korganizer and to set the status to confirmed. Since I was able to find the events in akonadikonsole, this should really be only a matter of which events are rendered by korganizer.