I can confirm this issue.

I'm going nuts to search why some does not receive invitation. Now I know. :(

Did you report bug to Mozilla?

Submited bug to mozilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1221918

I have not reported this as a bug myself anywhere, because I am in no way an expert on RFC2445, and I'm not at all confident that SOGo's behaviour is in fact correct. I didn't have any proper time to read RFC2445 at the time, and I have just discovered that it's obsoleted by RFC5545.

In fact, I think the Mac behaviour is wrong. RFC5545, p111, states clearly that ORGANIZER must be the meeting organiser. SENT-BY can be used to specify that someone else acting on behalf of the organiser (e.g. a secretary), but responses should still be sent to the organiser.

In the case of someone creating a meeting in a shared calendar, I think the question is the intent. Are they the organiser, or is the owner of the calendar of the calendar the organiser? That's a user context question; there is no definitive answer. At the very least, a Mac should set SENT-BY. And I now feel that iOD, Android and Lightning have a strong argument that they are right.

Regardless of what a standards lawyer would say, there remains the practical question of making SOGo work as the majority of users expect. Which probably boils down to 'what does Outlook/Exchange do in this circumstance'? I don't know the answer to that question.

We hit this problem because we're a small organisation using a single calendar as global 'who is where' resource. This usage cannot scale, so probably shouldn't be catered for as the default way of SOGo working. I suspect that what we should be doing is to have the shared calendar as a resource as per http://wiki.sogo.nu/ResourceConfiguration, configured to accept a huge number of multiple bookings, and tell people to create bookings in their personal calendar and invite the shared calendar.

Thinking a moment more, I am still trying to work out why SOGo doesn't send invitations anyway. Why should a third party, creating an event in a calendar to which they have access, only get invitations triggered if ORGANIZER is the calendar owner? Surely the question of ownership is not relevant to invitation?

IIRK this was done, because importing of events from another calendar system with another owner already set, should not trigger invitations again.

For security reasons it should be an option if a third party could trigger an invitation mail.

In one case we have team assistance with full access to the managers calendar, and it would be nice if there would be send an invitation in form of "Event Invitation: foo bar - on behalf of [Calendar Owner]" with sender address of the team assistance.

The exposed behavior in Thunderbird has another consequence: events created by user A in B's shared calendar don't appear in A's personal calendar.

@jaragundeThat is perfectly normal.

@ludovic Thanks for your response :) But I still think that behavior is inconsistent, at least. If you create an event in another person's shared calendar using the web UI, that event appears in your personal calendar, but doing the same from Thunderbird doesn't have the same effect.

Still an issue with Sogo v3.1.3

Would it at least be possible to add a configuration option that allows to send invitations if the organizer is not the owner of the calendar?

Thank you!