title: What's the difference between DomainKey-Signature & DKIM-Signature?
body: <p>I'm trying to sign emails with DKIM using PHPMailer Class and i can't get it to work.</p>
  
  <p>When i see the headers in my emails on gmail, i find that the class is successfully injecting DKIM in the email header but gmail doesn't even care.</p>
  
  <p>The question is that i've viewed the headers of linkedIn emails and i found out that they are using 2 DKIM headers, <code>DomainKey-Signature</code> &amp; <code>DKIM-Signature</code>.</p>
  
  <p>What's the difference? and is that why Gmail doesn't verify my emails? &amp; do you recommend any alternative &amp; robust classes to sign emails with domain keys on php?</p>
  
  <p>Thanks</p>