title: How to send follow up email using smtplib?
body: <p>I have my own server and IP. I'm currently sending business emails using smtplib, with each emails I save Message-ID in the database.</p>
  <p>I would like to send a follow up email to some of the sent email in the same thread. Is that something I can do with smtplib? If yes what's the solution?</p>