title: MailKit does not find message ID
body: <p>I am currently migrating from <a href="http://sourceforge.net/projects/hpop/" rel="nofollow">OpenPop</a> to <a href="https://github.com/jstedfast/MailKit" rel="nofollow">MailKit</a>. </p>
  
  <p>I have a unit test that loads a string into a MimeMessage like this:</p>
  
  <pre><code>var emailText = @"
  X-MDAV-Processed: mx1.footechnology.com.au, Mon, 30 Mar 2015 12:54:30 +1100
  Return-path: &lt;do-not-reply@baz.com.au&gt;
  Received: from mail2.baz.com.au (mail2.baz.com.au [220.157.74.146])
      by mx1.footechnology.com.au (mx1.footechnology.com.au)
      (MDaemon PRO v11.0.3)
      with ESMTP id md50005410292.msg
      for &lt;faxes@foobar.com.au&gt;; Mon, 30 Mar 2015 12:54:29 +1100
  Authentication-Results: mx1.footechnology.com.au
      spf=neutral smtp.mail=do-not-reply@baz.com.au;
      x-ip-ptr=pass dns.ptr=mail2.baz.com.au (ip=220.157.74.146);
      x-ip-helo=pass smtp.helo=mail2.baz.com.au (ip=220.157.74.146);
      x-ip-mail=pass smtp.mail=do-not-reply@baz.com.au (ip=220.157.74.146)
  Received-SPF: none (mx1.footechnology.com.au: do-not-reply@baz.com.au does not
      designate permitted sender hosts)
      x-spf-client=MDaemon.PRO.v11.0.3
      receiver=mx1.footechnology.com.au
      client-ip=220.157.74.146
      envelope-from=&lt;do-not-reply@baz.com.au&gt;
      helo=mail2.baz.com.au
  X-Spam-Processed: mx1.footechnology.com.au, Mon, 30 Mar 2015 12:54:29 +1100
      (not processed: sender do-not-reply@baz.com.au in exclude file)
  X-MDPtrLookup-Result: pass dns.ptr=mail2.baz.com.au (ip=220.157.74.146) (mx1.footechnology.com.au)
  X-MDHeloLookup-Result: pass smtp.helo=mail2.baz.com.au (ip=220.157.74.146) (mx1.footechnology.com.au)
  X-MDMailLookup-Result: pass smtp.mail=do-not-reply@baz.com.au (ip=220.157.74.146) (mx1.footechnology.com.au)
  X-MDDK-Result: neutral (mx1.footechnology.com.au)
  X-MDDKIM-Result: neutral (mx1.footechnology.com.au)
  X-MDSPF-Result: none (mx1.footechnology.com.au)
  X-Rcpt-To: faxes@foobar.com.au
  X-MDRcpt-To: faxes@foobar.com.au
  X-MDRemoteIP: 220.157.74.146
  X-Return-Path: do-not-reply@baz.com.au
  X-Envelope-From: do-not-reply@baz.com.au
  X-MDaemon-Deliver-To: faxes@foobar.com.au
  Received: from melbourne.baz.com.au (melbourne.baz.com.au [118.88.188.238])
      by mail2.baz.com.au (Postfix) with ESMTP id 3E100437181
      for &lt;faxes@foobar.com.au&gt;; Mon, 30 Mar 2015 11:54:17 +1000 (EST)
  Received: from baz.com.au (localhost [127.0.0.1])
      by melbourne.baz.com.au (Postfix) with ESMTP id 6BA057C07C
      for &lt;faxes@foobar.com.au&gt;; Mon, 30 Mar 2015 12:54:16 +1100 (EST)
  Content-Transfer-Encoding: binary
  Message-ID : &lt;syd1_did11-1403160784-288657210-5-21314.1403160831@medora2.syd1.colo.j2noc.com&gt;
  Content-Type: multipart/mixed; boundary=""_----------=_1301450056175850""
  MIME-Version: 1.0
  X-Mailer: MIME::Lite 3.01 (F2.72; B3.04; Q3.03)
  Date: Mon, 30 Mar 2015 01:54:16 UT
  From: ""Baz"" &lt;do-not-reply@baz.com.au&gt;
  To: ""Foo Bar"" &lt;fax@foobar.com.au&gt;
  
  This is a multi-part message in MIME format.
  
  --_----------=_1301450056175850
  Content-Disposition: inline
  Content-Length: 1133
  Content-Transfer-Encoding: binary
  Content-Type: text/plain
  
  This is the content of the message.
  
  --_----------=_1301450056175850
  Content-Disposition: attachment; filename=""fax-20110330125416.pdf""
  Content-Transfer-Encoding: base64
  Content-Type: application/pdf; name=""fax-20110330125416.pdf""
  
  JVBERi0xLjEgDSXi48/TDQoxIDAgb2JqDTw8IA0vVHlwZSAvQ2F0YWxvZyAN
  
  --_----------=_1301450056175850--
  ";
  
              var stream = new MemoryStream(Encoding.UTF8.GetBytes(emailText));
              var message = MimeMessage.Load(stream);
  
              Console.WriteLine("Text body:" + message.TextBody);
              Console.WriteLine("Html body:" + message.HtmlBody);
              Console.WriteLine("Date:" + message.Date);
              Console.WriteLine("MessageId:" + message.MessageId);
              Console.WriteLine("From:" + message.From.Mailboxes.First().Address);
              Console.WriteLine("To:" + message.To.Mailboxes.First().Address);
  </code></pre>
  
  <p>Whilst the message is successfully parsed, the MessageId header is not found. OpenPop could find the MessageId in the email. Why does MailKit fail? Is the message id header somehow considered invalid and thrown away?</p>