If you want a UNVERFIED warning when non moderators send a PM here is the code. Place it in postbit and/or postbit legacy above or below the code for this mod....
PHP Code:
<if condition="THIS_SCRIPT=='private' && is_member_of($post, 2)">
<br />
<table cellpadding="$stylevar[cellpadding]" cellspacing="$stylevar[cellspacing]" border="0" width="98%" align="center" style="border-bottom-width:0px">
<tr>
<td class="alt1" width="30"><img src="$stylevar[imgdir_misc]/verified.gif" width="27" height="32" alt="Verified!" /></td>
<td class="alt2"><strong><font size="2" color="#fa2424">U N V E R I F I E D</font></strong><br /><font size="1">If this message contains spam please report it to the admin</font></td>
</tr>
</table>
<br />
</if>
Make sure your moderators primary usergroups are all set to moderator and not the additional.