Which is best?
* automattically unsubscribing someone once they click the 'unsubscribe' link in an email
* bringing them to a page and asking for confirmation
* bringing them to a page and having them input their email address
Automatically unsubscribing is faster, but if someone forwards a newsletter, the recipient can unsubscribe the original sender because the link is hard coded to unsubscribe their account.
Campaign Monitor always instantly unsubscribes people. That does mean others can unsubscribe them if the email is passed on, but the benefits far outweigh that risk.
Forcing people to go through additional steps to unsubscribe is frustrating for them, and more likely to lead to complaints.