The one thing that you do need to consider with a complete one-click unsubscribe is whether your e-mail could be forwarded - if a user forwards an e-mail, it's

The one thing that you do need to consider with a complete one-click unsubscribe is whether your e-mail could be forwarded - if a user forwards an e-mail, it's possible that whoever recieved the message could unsubscribe on their behalf. Probably the best thing to do, IMO, is a simple two click unsubscribe - take them to a page with their e-mail address already filled in, and just require them to click "OK" to confirm which address is being unsubscribed.