def test_multiple_receivers(self):
        recipients = ['joe@example.com', 'jane@example.com']
        call_command('sendtestemail', recipients[0], recipients[1])
        self.assertEqual(len(mail.outbox), 1)
        mail_message = mail.outbox[0]
        self.assertEqual(mail_message.subject[0:15], 'Test email from')
        self.assertEqual(sorted(mail_message.recipients()), [
            'jane@example.com',
            'joe@example.com',
        ])
The mail may be sent with multiple recipients.
dataset/ETHPy150Open django/django/tests/mail/test_sendtestemail.py/SendTestEmailManagementCommand.test_multiple_receivers