A common complaint that we hear, particularly from email senders who are signed up for feedback loops from ISPs, is “why won’t the ISPs let us know who is complaining and clicking “this is spam” on our email, so that we can unsubscribe them?”
There are a couple of reasons for that. To some extent, it harkens back to ISPs having to deal with (primarily) genuine spammers – people who are sending email to anybody they can, whether it’s wanted or not, or requested or not. ISPs won’t share the email addresses of the complainers with those people, and rightly so, because those kind of genuine spammers simply want to take the email address off the mailing list to stop people from complaining. This is called “list washing”, and ISPs (and most of the rest of us) hate listwashing. It simply means that the spammer has no intention of stopping spamming – they just want to get rid of the squeaky wheel.
For that reason, ISPs are not going to give up the email address of someone who hit the “this is spam” button on your email.
The other reason, however, is that ISPs take their customers’ privacy very seriously. And so they are not going to share their customers’ email addresses.
So, with that being the case, what can you do when someone who actually did ask for your email suddenly complains that it’s spam? How can you unsubscribe them if the ISP won’t tell you who it is?
What savvy email senders do is they create a unique token – which is keyed to a particular subscriber’s email address – and that gets embedded in each email sent to that subscriber. Typically – not always, but typically – when someone hits “this is spam”, the message you get from the ISP, via the feedback loop, will include the message that you sent to the subscriber. And while the email address will be redacted, the content of your email will remain intact – including that unique token which your system can translate to the subscriber’s actual email address.
This is another example of a situation where you need to understand why the system works the way that it does, and then, instead of bucking and railing against the system, learn to work with it.