title: Postfix header_checks remove headers
body: <p>First of all I'm running lamp ubuntu 14.04 with dovecot and postfix for mailing.
  I'm quite unexperienced if it comes to setting up a mail server.</p>
  
  <p>I'm reaching a score of 5.1 / 10 and my mail does arrive on my gmail account, but not to my hotmail email. Here are the biggest problems reported by mail-tester
  <a href="https://i.stack.imgur.com/NQZzi.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NQZzi.png" alt="Mail problems according to mail-tester"></a></p>
  
  <p>The  mail will mainly be newsletter kind of things so the html problems I suppose should be fixed if I actually send a properly formatted html mail instead of some plain text lorem ipsum. Would be great if there's a solution for that as well, but it's not my biggest concern.</p>
  
  <p>I'm using the header_checks in postfix trying to remove the X-MSMail-Priority, but without success. I can't find anything else besides the header checks method. Here's the line I'm using that I thought should remove X-MSMail-Priority</p>
  
  <pre><code>/^X-MSMail-Priority:/                   IGNORE
  </code></pre>
  
  <p>Please say so if I've forgotten something important or something is unclear. I'll update my question as quickly as possible</p>