title: Why is Outlook suppressing HTML formatting when an .ics attachment is present?
body: <p>I am trying to set up an email with an .ics file attached. I also want the body of the message to contain a small amount of HTML formatting (a single line coloured red).</p>
  
  <p>I have got all of this set up properly, and all seems to be working on various other mail programs (gmail, mac Mail). However in Outlook (specifically Outlook 2013 on Win10) it fails to render the colour.</p>
  
  <p>If I send an identical message without the .ics attachment, all renders fine.</p>
  
  <p>I have a feeling this may be a 'feature' of Outlook that when showing a calendar preview for the .ics file it won't show anything that might detract from their wonderful preview pane (like some important text that has been rendered in red to make sure people have seen it); but is there something I'm missing?</p>
  
  <p>Full code from the email below:</p>
  
  <pre><code>------=_Part_732_741500152.1445600688123
  Content-Type: text/html; charset=utf-8
  Content-Transfer-Encoding: 7bit
  
  &lt;html&gt;
  &lt;p&gt;Dear Jazzer,&lt;/p&gt;
  
  &lt;p style="font-weight:bold"&gt;This is some bold text&lt;/p&gt;
  &lt;p style="color:red"&gt;This is some red text&lt;/p&gt;&lt;/html&gt;
  ------=_Part_732_741500152.1445600688123
  Content-Type: text/calendar; method=request; name="Test Learning Event.ics"
  Content-Transfer-Encoding: 7bit
  
  
  BEGIN:VCALENDAR
  PRODID:-//Microsoft Corporation//Outlook 15.0 MIMEDIR//EN
  VERSION:2.0
  METHOD:REQUEST
  X-MS-OLK-FORCEINSPECTOROPEN:TRUE
  BEGIN:VEVENT
  UID:a14L0000001ufrEIAQ
  CLASS:PUBLIC
  SUMMARY:Test Entry
  LOCATION:Bristol,UK
  DESCRIPTION:test
  CREATED:20151023T114447Z
  DTSTART:20151022T140000Z
  DTEND:20151023T120000Z
  DTSTAMP:20151023T114447Z
  LAST-MODIFIED:20151023T114447Z
  PRIORITY:5
  SEQUENCE:1
  TRANSP:OPAQUE
  X-MICROSOFT-CDO-BUSYSTATUS:OOF
  X-MICROSOFT-CDO-INTENDEDSTATUS:OOF
  X-MICROSOFT-CDO-IMPORTANCE:1
  X-MICROSOFT-DISALLOW-COUNTER:FALSE
  X-MS-OLK-AUTOFILLLOCATION:FALSE
  X-MS-OLK-CONFTYPE:0
  END:VEVENT
  END:VCALENDAR
  ------=_Part_732_741500152.1445600688123--
  </code></pre>