There is just a little technical problem with this.
In order to store an email into your mailbox, SOGo has to authenticate with your credentials on the IMAP server.
As it doesn't know (and should not) your credentials, it can only do that while you are logged in.
Therefore all responses to Accept/Decline/Tentative of participants can usually not get stored there.

Thank you for the explanation.

I understand the issue regarding storing automatic Accept/Decline/Tentative responses, especially when SOGo does not have the user's IMAP credentials available.

However, my main use case is slightly different:

I am not primarily asking to store every automatically generated calendar response. The important case is when an authenticated user creates, updates or cancels an event, and SOGo sends an invitation, update or cancellation on behalf of that same organizer.

From the user's perspective, this is an outgoing message they initiated themselves, so they expect it to appear in their Sent folder.

Would it be technically feasible to make this optional only for organizer-initiated iMIP/iTIP messages, for example when SOGo has an authenticated user context available?

If storing attendee replies such as Accept/Decline/Tentative is not always possible because the user's IMAP credentials are not available, that would be understandable. But storing organizer-initiated invitations, updates and cancellations would already solve the main traceability issue.

Ok, that reduced function can be achieved by:
1) Open context menu of the calendar in question (== three dots after the calendars name).
2) click on "Properties"
3) in the new overlay select "When I modify my calendar, send a mail to" and give an email address in the field "Email address*" below it. This can be your own.
4) store your change by pressing "Save".

Thank you for the suggestion.

I understand that this can notify the calendar owner when the calendar is modified.

However, this does not fully solve the requested use case.

The requested feature is not only to receive a notification that the calendar was modified. The goal is to have a trace of the actual outgoing iMIP/iTIP messages that SOGo sends to attendees.

With the proposed setting, the user receives a separate calendar modification notification. But this does not show whether an invitation, update or cancellation was actually sent to the attendees, which attendees received it, and what exact iMIP/iTIP message content was generated.

The expected behavior would be similar to normal email sending: when SOGo sends an invitation, update or cancellation on behalf of the organizer, a copy of that outgoing message should be stored in the organizer's Sent folder.

So the requested feature is about storing outgoing organizer-initiated calendar messages, not about receiving an additional notification when the calendar changes.

For our use case, the important cases are:

• organizer creates an event with attendees
• organizer updates an event with attendees
• organizer cancels an event with attendees

In all of these cases, SOGo sends an outgoing iMIP/iTIP message on behalf of the organizer. We would like an optional way to store a copy of these outgoing messages in the organizer's configured Sent folder.