When an event is created in Kube and an invitation is sent out to an attendee, Kube sends out an invitation.
However, the Kolab Server also does this too.
Result: The invitee ends up with two invitation emails.
This is either a job to be handled by the server or by Kube.
What do the CalDAV specifications say should occur?
Please see: https://bifrost.kolabsystems.com/T352055
I'm not sure what the rfc's have to say about it, but I agree it would be better if it was one or the other.
Feel free to let me know if you figure out how this is supposed to work.
Apple's calendaring apps leave this functionality to the CalDAV server. This means that an invitation gets sent out by the server (tested with Fastmail and Kolab) but I don't believe it's placed in the sent items folder as the mail app and Calendar app are separate from each other.
Potentially what is best is if you are able to implement whatever it is that triggers the CalDAV server to send out an invitation and leave IMAP out of this?
Disabling the functionality of sending out emails on the server seems like it would be much harder to disable than to do so in Kube.
I could not find any RFCs.
I have tested Apple Calendar again with both Fastmail and Kolab Now accounts
I can confirm:
-the recipient receive invitation email from both accounts
-neither account places any email in the sent folder.
As Kube already is able to send invitations through CalDAV server, it seems logical to stop it doing so in IMAP.
Neither webmail service places an invitation in the sent folder either, and so this does not also appear to be a Standard.
Further, in replying to invitations also appears to be left to the server (tested with both web client and CalDAV client) and therefore Kube should probably not submit a reply via IMAP too