Thanks for the replies. I recently “fixed” the problem:
I also migrated from Zarafa to Kopano and I am using multi tenancy mode.
The problem seems to be caused by wrong permissions on the public store
for newly created users.
I have compared the public store of the company which causes trouble with
a newly created companys store.
The public store (All public folders) of the newly created company contains
permissions for the company user (“NewCompanyName”).
The public store of the company which causes trouble does not contain a company
user, only the user/group “Everyone”.
As I was not able to add the User “TheCompanyName” (it does not show up in GAB…),
I unhooked the public store and created a new one:
kopano-admin -s -I TheCompanyName
And copied the contents of the old public store to the new one:
kopano-admin --hook-store LONGSTOREID --type company --copyto-public
After that, the user has permissions to store the free/busy information to the
public store.
Regards,
Christoph
PS: Does anyone know a way to add the company user (or group?) to the permission list?