title: Python smtp can't send mail to group email address
body: <p>My smtplib code:</p>
  <pre><code>import sys
  import smtplib
  from email.mime.text import MIMEText
  
  SMTP_SERVER = &quot;mailserver.company.com&quot;
  SMTP_PORT = 25
  
  def send_mail(mail_subject, mail_from, mail_to, mail_cc, mail_message, mail_priority=&quot;Normal&quot;):
      mime=MIMEText(mail_message, &quot;html&quot;, &quot;utf-8&quot;)
      mime[&quot;Subject&quot;]=mail_subject
      mime[&quot;From&quot;]=mail_from
      mime[&quot;To&quot;]=', '.join(mail_to)
      mime[&quot;CC&quot;]=', '.join(mail_cc)
      mime['X-Priority'], mime['X-MSMail-Priority'] = transfer_smtp_priority(mail_priority)
      email=mime.as_string()
  
      try:
          smtp=None
          smtp=smtplib.SMTP(SMTP_SERVER, SMTP_PORT)
          smtp.ehlo()
          smtp.starttls()
          smtp.sendmail(mime[&quot;From&quot;], mail_to + mail_cc, email)
      finally:
          if smtp != None:
              smtp.quit()
  
  def transfer_smtp_priority(priority):
      if priority == &quot;Normal&quot;:
          return '''3''', '''Normal'''
      elif priority == &quot;Low&quot;:
          return '''5''', '''Low'''
      elif priority == &quot;High&quot;:
          return '''1''', '''High'''
          
  send_mail(&quot;TEST&quot;, &quot;DAN.W@company.com&quot;, [&quot;DAN2.W@company.com&quot;], [&quot;mail.group@company.com&quot;, &quot;DAN.W@company.com&quot;],  &quot;Test mail for python smtp module&quot;)
  </code></pre>
  <p>The personal email address can receive this test mail but the user exist in group email can't.
  Is there any solution to resolved it...</p>