css style of the email sended by contact form

Hi,

How I can put some css or html tags into the email that is sended when somebody uses the form in Contact page?

For example, I have receive this:
Name: test
E-Mail: (Email address hidden if logged out)
Subject: test
Message: test

And, at least, I want to receive that (put some words in bold, for example):

Name: test
E-Mail: (Email address hidden if logged out)
Subject: test
Message: test

Thanks!