As the moment, I wrote the thread you've linked I haven't recognized when I receive the mail mentioned there. As stated, I receive this mail every time I visit the ticket list.I checked the tables. ost_ticket with ticket_id = 1 has dept_id = 1, topic_id = 1ost_department with dept_id = 1 has a valid entry which is my primary department.ost_ticket_thread with id = 1 has user_id = 1 which I believe is me. pid = 0 and staff_id = 0. I assume pid is parent_id and fine but should be staff_id any other value than 0?