Outlook 2010 ,Using <a> tag as a button css

I am using a link tag styled to look like a button in my email . The css for the tag is as follows.

<a href="#">Submit</a>

a.submit{
 background: none repeat scroll 0 0 #FF9900;
    border: 1px solid #FF9900;
    color: #FFFFFF;
    display: inline-block;
    padding: 6px;
    text-decoration: none;


}

The link style works everywhere except in outlook . Where only the text gets the background color

I noticed the same issue in the google+ email too. Their buttons show the same css styling problem in outlook