Magento – How to add Unsubscribe link at the bottom of transaction email footer

Take a look at Magento Newsletter form not working

Try

{{block type="newsletter/subscribe" template="newsletter/subscribe.phtml"}}

The form need to be posted to newsletter/subscriber/new which is define in

Mage_Newsletter_Block_Subscribe

/**
 * Retrieve form action url and set "secure" param to avoid confirm
 * message when we submit form from secure page to unsecure
 *
 * @return string
 */
public function getFormActionUrl()
{
    return $this->getUrl('newsletter/subscriber/new', array('_secure' => true));
}

in rwd theme compare should look like

change this

<reference name="right">
            <block type="catalog/product_compare_sidebar" before="cart_sidebar" name="catalog.compare.sidebar" template="catalog/product/compare/sidebar.phtml"/>
            <!--<block type="core/template" name="right.permanent.callout" template="callouts/right_col.phtml">-->
                <!--<action method="setImgSrc"><src>images/media/col_right_callout.jpg</src></action>-->
                <!--<action method="setImgAlt" translate="alt" module="catalog"><alt>Keep your eyes open for our special Back to School items and save A LOT!</alt></action>-->
            <!--</block>-->
        </reference>

to

<reference name="footer">
            <block type="catalog/product_compare_sidebar"  name="catalog.compare.footer" template="catalog/product/compare/sidebar.phtml"/>

        </reference>

if this code is not work then add a extra code in

<?php echo $this->getChildHtml('catalog.compare.footer')?>