I am looking for a solution that allows my Nextcloud users to accept external calendar invites through imap mail clients, and that automatically posts the event to the Nextcloud calendar.  Not sure if there is a process to get from the dovecot inbox to the Nextcloud calendar.  Even if that requires SOGo as a middle-man, I would be willing to work with that.  But as of now I cannot find a way to make this work.

Any ideas?  I see talk of z-push which seems not to exist anymore, and vdirsyncer which seems to not have a simplified method to setup.