If you only want this on the Orders ... then you could customize the:
/includes/classes/orders.php
Around line 968 you would see:
PHP Code:
// include disclaimer
$email_order .= "\n-----\n" . sprintf(EMAIL_DISCLAIMER, STORE_OWNER_EMAIL_ADDRESS) . "\n\n";
If you were to add on to the $email_order before that line it would appear above the disclaimer on the text email ...
For the HTML email, you would need to customize the file:
/email/email_template_checkout.html
And add something above the:
PHP Code:
<div class="disclaimer">
<div class="disclaimer1">$EMAIL_DISCLAIMER</div>
<div class="disclaimer2">$EMAIL_SPAM_DISCLAIMER</div>
</div>