title: mandril Reject Reason: unsigned
body: <p>Because of mandrill start to work with mailchimp so I have to do a new account in mailchimp after that I updates my code in the developer and production page.
  But when I start to sending email it doestnt recieve and in the manderill acount I got Reject Reason: unsigned</p>
  
  <p>Can anyone help me to fix it?</p>
  
  <p>Thank you</p>