That is not an unsubscribe link. Unsub links remove you from the list without having to log in
One of my more annoying frequent inbox flyers is a newsletter from some website or other that says I need to log in to change my preferences.. only my account there must have been purged as they have no record of my email address (the exact email being sent the newsletters)
Sites - just provide easy one-click unsubscribe links, chances are it'll improve your open/click rate as you're letting people who aren't interested sift themselves out.
Perhaps that link did something for me, I have no idea. Why do you not have an unsubscribe link in your e-mails? Where I live, this is a legal requirement.
Does this link work for you?
https://ifttt.com/emails/unsubscribe?email_type=newsletter (visiting this link unsubscribes you if you're signed in)