'The mail is sent with the correct subject and recipient.'

def test_single_receiver(self):

    recipient = 'joe@example.com'
    call_command('sendtestemail', recipient)
    self.assertEqual(len(mail.outbox), 1)
    mail_message = mail.outbox[0]
    self.assertEqual(mail_message.subject[0:15], 'Test    email    from')
    self.assertEqual(mail_message.recipients(), [recipient])
