Proper way of sync with Thunderbird/Lightning AND working invitations


I’ve installed the calendar in an environment with Windows, Linux, macOS, iOS, Android client users.
We stumbled into big problems with the invitation feature.

NC server: 18.0.6
TB Version: 68.x

What is the recommended way? I read a lot in the forum and the Issues in github but no solution seems to work without problems (I tested it quite intensively with a colleague).

What seems to work best at the moment to activate “Prefer client-side email scheduling” in Thunderbird for the calendars, but when I send an invitation to persons that are not on our Nextcloud instance (but on the same ActiveDirectory repository without access to NC) they get two emails (server and the one from my client). When I invite someone with a google calendar he only get’s the client mail… (I do not really get the logic/reason behind that)
This would make sense in my understanding (how should the server know about the Thunderbird settings?), but stange thing is that when I tested it with my colleague (is on the NC server) he only got my client email (no NC invitation).
When I do not activate the “Prefer client-side email scheduling” and get a mail invitation for an event and click “accept” the invitee does not get my response (as the client assumes the server handles that?)

Does it help to also activate the mail app and add there the email?

(so this Error when accepting a calendar invite on Thunderbird is not really a complete solution…)

Or do I have to additionally uncheck the “Send invitations to attendees” in the groupware settings?

Still this does not really explain the non-consistent behavior to me…


Don’t know if you’re still looking for a solution but I’ve the same questionning.

I use NC for personal and professional (one instance, one NC account but 2 emails addresses).

I also use Thunderbird.

When I create an event in NC Calendar app with inviting people, invitees receive email from NC with personal information inside the invitation (personal email, personal account): not good.

So, I’ve decided to use Thunderbird Calendar synced to NC calendar; setting “Prefer client-side email scheduling” has been check and TB Calendar email has been set to my professional email address. This solution works except that invitees still receive an invitation from NC with personal information on top of TB invitation sent.

Thus, the best solution, IMHO is to configure NC not to send invitation and let TB handles invitation but is there anyway to configure NC so ?

Thanks in advance.