Fortunately, with strong spam catching features in most of the mail systems, the bother of spam is considerably less than it was 10 years ago. It is clear that the perennial concern about opting out being a magnet for new sources of spam is well and truly founded. Fortunately, you can use the “+” option for email to opt-out safely as well as getting a solid read on the how the opt-out either cuts down on or increases spam.
My particular story is related to identify theft monitoring that highlighted Instant Checkmate as having some personal information. Fortunately, there is an “opt-out” option for removing your personal information. I’m not going to make any particular comment regarding Instant Checkmate’s business model. The BBB and other references do a better job than I would.
So to opt out, there is a confirmation required for the information that they already have (most likely from public sources). They also ask for an email address so that they can confirm the opt-out.
Fortunately, gmail allows you to add a “+” as a suffix to your email address and hook in some characters that Google will ignore. So to opt out from instantcheckmate, I used the “tippettm+checkmate” email address. Verification and so on went through fine. A few days later, I received the confirmation of the opt-out. I confirmed that I could no longer search instant checkmate for my details. So it achieved what I was expecting.
Now comes the interesting part. About 50% of my spam now is directed to the “tippettm+checkmate” address. This method provides a good way to measure the success of “opt-out” as well as provide a secondary way of channeling mail that you have no interest in seeing straight to /dev/null.
What other techniques do people use to track opt-out success (and the corresponding impact on spam?
use-cases.org - Matthew Tippett's Blog 