newsletter subscription

One question: I’ve one customers email into list subscription, that receive my newsletter. If this customer follow the link to unsubscribe, his email goes into suppression list. But if I add again this email address to newsletter list (subscription list), what email address list have priority? So this customers email will receive or not my newsletter?
Thank you

I believe it will unsubscribe him from just that newletter, and not all newsletters/campaign emails.

and what’s the way to unsubscribe for all newsletters? How the customers can unsubscribe?

and what’s the way to unsubscribe for all newsletters? How the customers can unsubscribe?
The strange is that the same email address is present on the newsletter list and into “Suppression List - By Id” also the customer have clicked on the unsubscribe link.