Unsubscribe Link In Email Footer Doesnt Do Anthing

When editing the email content of the review form, the email footer contains the unsubscribe link <a>unsubscribe</a>. This doesnt actually link to anything and I cannot see what shortcode we would need to embed in between the <a></a> to allow the correct use of the unsubscribe feature.

When the emails get sent the customer for actual orders it still just shows <a>unsubscribe</a> which doesnt go anywhere?