Don't unsubscribe from spam!!

Having been around the email and anti-spam industry for a while, I’ve just about seen and heard it all. In fact, sometimes I’ve been around for the beginning of the myth.
One myth that seems to never actually go away is “unsubscribing just confirms you’re a real address and your address will get sold and your spam load will explode.” This is related but orthogonal to “spammers harvest addresses out of unsubscribe forms.” The reality is that both of these things used to be true. Unsubscribing would confirm your email address and increase your spam load. Spammers would harvest addresses out of unsubscribe forms.
But neither of these things have really been true for the last decade.
I have had clients over the years that are spammers. Some of the are names that you probably would recognize. Some of them are companies we could probably all agree are spammers.  Some of them are buying addresses from companies that are spammers. Some of them are companies that have a good mailing program here and then hire snowshoers over there. Sometimes they come to me claiming to be real mailers “with minor delivery problems.” Sometimes they come to me saying that a blocklist has recommended they talk to me about repairing their processes. Sometimes they even actually want to fix things. Sometimes they’re just looking to say that I’ve given them a clean bill of health (which is not something I do).
What that means is that I have lots of addresses on lots of spammer lists. Not just the ones they’ve found, but ones I’ve used to test their systems. I use tagged or disposable addresses for everything. Some of my disposable accounts are only marginally connected to me as I want to see what senders really do for their subscribers rather than what they want me to think they do. The ones I add to their system I use to test their subscription process as well as their unsubscription process.
I have never encountered a situation where unsubscribing one of those addresses caused a “multiplication” (to quote one anti-spammer) of my spam load.
I’ve had cases where my clients have ignored unsubscribes. I’ve had cases where my clients have decided years later to add me to their list again. I’ve had cases where they’ve been bought out and my address has been reactivated by the new owners. I’ve had cases where months or even years of 5xx responses was ignored. I’ve seen just about every bad bit of behavior on behalf of spammers. But I’ve never actually had unsubscribing increase my spam load.
It doesn’t matter how often people demonstrate unsubscribing doesn’t result in more spam in the current email ecosystem. (Ken Magill 2013, NYTimes 2011, dayah.com 2009). It doesn’t matter that many mailers treat “this is spam” button hits the same way they handle unsubscribe requests. The myth still persists.