As far as I know, you can't just email a link to a post - the feature emails a link to the thread. But, you can try stealing the code from the Thread Tools and adding it to the postbit and playing with modifying it to send just a post link. Here it is from Thread Tools:
HTML Code:
<if condition="$show['sendtofriend']">
<tr>
<td class="vbmenu_option"><img class="inlineimg" src="$stylevar[imgdir_button]/sendtofriend.gif" alt="$vbphrase[email_this_page]" /> <a href="sendmessage.php?$session[sessionurl]do=sendtofriend&t=$threadid" rel="nofollow">$vbphrase[email_this_page]</a></td>
</tr>
</if>