Hello @JillW78647. Great question. When a contact unsubscribes, you are not able to manually add them back onto any of your contact lists due to the CAN-SPAM act. Not to fear though! We do give you and the contact the option to be added back. In the contact profile, there is a link that says "Resubscribe". Clicking this sends the contact a Confirmed Opt-In email which includes a link they will need to click on to confirm their interest in receiving your emails again. Here is more information about this feature and also a screenshot of what this link looks like under the contact profile.