You need to escape your quotes or change the inner double-quotes to single quotes
[edit]
Something like this:
<?php
echo '<a href="mailto:type%20email%20address%20here?subject=I%20wanted%20to%20share%20this%20post%20with%20you%20from%20'. bloginfo('name') .'&body='.the_title('','',true).'%20%20%3A%20%20'. get_the_excerpt() .'%20%20%2D%20%20%28%20'. the_permalink() .'%20%29" title="Email to a friend/colleague" target="_blank">Share via Email</a>';
?>