When creating HTML emails, should we use html, head, body tags?

Question

In my email views, I usually just do something like...

   
Name
   
Value

Should

Answer 1

There's 1 thing I know to be true: Using HTML opening and closing tags will help in general spam scoring due to the fact that many such appliance based filters and software firewalls will add a point or so to an email that uses html but does not use the opening and closing tags.