title: Python smtplib proxy support
body: <p>I would like to send email through a proxy. </p>
  
  <p>My current implementation is as follows:</p>
  
  <p>I connect to the smtp server with authentication. After I've successfully logged in, I send an email. It works fine but when I look at the email header I can see my host name. I would like to tunnel it through a proxy instead. </p>
  
  <p>Any help will be highly appreciated.</p>