I just realized while checking around, the <table cellspacing='10'> </table> doesn't work when I view my gmail in IE (I am using IE9).
But using FF or Chrome, its fine. I use my IE to view my Hotmail and Yahoo account that has the same newsletter, it has cellspacing just fine, so what happens to my IE when viewing my gmail acccount newsletter? Any clue?
If you add style="border-collapse: separate;" to the tag, it works in Gmail in IE. Still working on getting it to work in Outlook 2007/2010, haven't had the same luck.