'Regression test for #14301'

def test_idn_send(self):

    self.assertTrue(send_mail(u'Subject', u'Content', u'from@\xf6\xe4\xfc.com', [u'to@\xf6\xe4\xfc.com']))
    message = self.get_the_message()
    self.assertEqual(message.get(u'subject'), u'Subject')
    self.assertEqual(message.get(u'from'), u'from@xn--4ca9at.com')
    self.assertEqual(message.get(u'to'), u'to@xn--4ca9at.com')
    self.flush_mailbox()
    m = EmailMessage(u'Subject', u'Content', u'from@\xf6\xe4\xfc.com', [u'to@\xf6\xe4\xfc.com'], cc=[u'cc@\xf6\xe4\xfc.com'])
    m.send()
    message = self.get_the_message()
    self.assertEqual(message.get(u'subject'), u'Subject')
    self.assertEqual(message.get(u'from'), u'from@xn--4ca9at.com')
    self.assertEqual(message.get(u'to'), u'to@xn--4ca9at.com')
    self.assertEqual(message.get(u'cc'), u'cc@xn--4ca9at.com')
