Need to stop sending default email while importing task into project module

Am using excel to import task data with a custom program

                    project_task_obj.with_context(mail_notrack=True).create({

                            # set mandatory fields

                            'project_id': project_id.id if project_id else False,

                            'name': task_title,

                            'stage_id':state_id.id if state_id else False,

                            'ws_start_date':start_date,

                        })

tried this but still default email is being sent by the server