Terminal mail 'my/path/manage.py': [Errno 1] Operation not permitted

settings.py

CRONJOBS=[
 ('* * * * *', 'my_app.cron.my_scheduled_job')
]

cron.py

def my_scheduled_job():    
    Test.objects.create(name='tested',date_generated=datetime.datetime.now())

After running "python manage.py crontab add" and "python manage.py runserver", Not object is added into Test model and I get terminal mail error "Terminal mail 'my/path/manage.py': [Errno 1] Operation not permitted"