title: What html/css attributes are mail safe?
body: <p>I have recently been developing a newsletter for a client of mine. How ever I can't seem to find good information on what css and html are safe to use in the major mail clients.</p>
  
  <p>I thought that maybe there are people here that have the knowledge and we can create some sort of list of things that work in major mail clients.</p>
  
  <p>This is a list of popular mail clients I borrowed from campaign monitor. (If I forgot somthing please tell me)</p>
  
  <pre><code>Microsoft Outlook
  Apple Mail
  Hotmail
  Yahoo! Mail
  Gmail
  </code></pre>
  
  <p>The question is what tags, attributes, special quirks are there in these major browsers and how can they be easily avoided.</p>
  
  <p>Thanks for the help,</p>