How do you implement those? Many years ago I ran a list which had a one click unsubscribe link and some people kept unsubscribing. It turned out they had some anti-malware service which was opening all links in the email to see if they were malicious, including the unsubscribe link.
Same way, a link unique to the recipient. Not sure how you get around that particular issue, but thankfully that's not my problem as I'm not a marketer or deliverability expert (yet). But it's an interesting question that I now want to know the answer to.
How do you implement those? Many years ago I ran a list which had a one click unsubscribe link and some people kept unsubscribing. It turned out they had some anti-malware service which was opening all links in the email to see if they were malicious, including the unsubscribe link.