[djbaxter]

I would guess you want to change this part in the product_anti_managed_bounced_email.xml file, around lines 43-44:

$bounceurl		= $vbulletin->options['ezb_admincpurl'] . "/ezbounce.php?u=" . $buser['userid'];
$bouncestring	= "<a href=\"$bounceurl\" target=\"_blank\">$bounceurl</a>";

Change to:

$bounceurl		= $vbulletin->options['ezb_admincpurl'] . "/ezbounce.php?u=" . $buser['userid'];
$bouncestring	= "<a href=\"$bounceurl\">$bounceurl</a>";

I'm not sure why the target="_blank" part is required or helpful in any case but it wraps in Outlook express and is ignored anyway so it works for me as is...

Added: If you use this method, you will need to reinstall the product, of course. As an alternative, see the instructions by Antivirus below.