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How Can Newsletter Senders Tell that I Haven’t Opened a Newsletter?


I am sure that I read in one of your newsletter emails that people don’t know if we read emails that we send them. I don’t know who reads my emails that I send on. So can you please explain this email that I received today? I just copied the body of the email, and yes, I guess I had subscribed at some point, but I haven’t had much in the way of emails from them in a long long time. Here is the email content:

Dear Reader,

We’ve noticed you haven’t been reading our emails lately.

Maybe you’re getting too many emails in your inbox. Maybe the information we’re sending isn’t useful to you anymore.

Whatever the reason, we don’t want to send you anything you don’t want.

If you’d like to unsubscribe, please do so now.

Or, if we’re wrong and you want to keep your current subscription, just let us know.

Please choose from one of the following options:

Keep me subscribed

Unsubscribe me

How did they know I hadn’t been reading?

There’s perhaps a too-subtle turn of phrase that I use when talking about email tracking that probably leads to your confusion.

I didn’t say they “can’t” tell if you’ve opened the mail – what I said was they “can’t reliably” tell.

That’s a pretty important difference.

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How open tracking works

What’s called “email open tracking” works one of two ways:

  • An image reference is placed in the email that is actually stored on the sender’s server. When the email is displayed (i.e. the mail is opened) with images turned on, that image is fetched. The act of retrieving the image to display also carries with it some information that says,  “This was opened for the copy of the newsletter that was sent to Leo.” As a result, they know that Leo opened the email.
  • Links in the email are “redirected” – meaning that instead of going to their destination directly, they first go through a click tracker, and then get redirected or forwarded on to the actual destination. Once again, the act of performing that redirection also carries with it some information that says, “This click came from the copy of the newsletter that was sent to Leo.” By clicking a link in that newsletter, they know that Leo had to open that newsletter to get at that link.

That can give newsletter senders (such as myself) a pretty good idea of whether or not the newsletter is being read and what is getting clicked on more often.

But it’s not a perfect system, which is why I say it’s not reliable.

I Spy How open tracking fails

Open tracking relies on one of two things: images being displayed or links being clicked.

The default configuration for many email programs is to not display images by default. Thus, you can open and read many newsletters1 without ever fetching an image.

And if you never click a link, you never click a link.

So, with no images displayed and no links clicked, you may well have opened and read the newsletter. The sender simply has no way to know that you did.


Opening is not reading

One thing that no technology can tell you is if the email was actually read. At best, all we can say is that it was opened and probably displayed.

There’s simply no way to know that someone’s eyes actually scanned or read an email and understood it.

Heck, even when people reply to a message, it’s often clear that they didn’t read and understand it. :-)

Why newsletter publishers care

The other question is why might publishers actually care about this stuff.

Well, as a newsletter publisher myself, I can tell you: it’s all about spam. Rather it’s all about reputation.

You see, if you use a web-based email provider – like Gmail, say – they can tell that you’ve opened the mail, simply because you’re using their interface to do exactly that. They don’t send that information back to anyone, but they know. If they see a newsletter that the majority of recipients don’t open, that most people don’t read, then they infer that the newsletter’s probably not that valuable.

In fact, it might even be spam.

If that happens enough,  the newsletter or its sender is given a poor reputation, and the email provider will start putting it into the spam folder instead of the inbox, possibly for most (if not all other) subscribers.

As a result, if a newsletter publisher can’t tell if you’ve opened their newsletter in a while, they’ll often send a message such as the one you received. Any of three things will happen:

  • You’ll never see it because you’re actually not opening that newsletter. Eventually, your subscription will be removed.
  • You’ll opt to keep receiving the newsletter.
  • You’ll opt to stop receiving the newsletter.

The net result for the publisher is a newsletter that’s sent only to people who actually want it. That means a better reputation, which in turn means that the newsletter is less likely to be marked as spam for everyone.

And yes, I do this once a year, typically in the spring.

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Footnotes & references

1: Including mine.

2: Tracking services that claim otherwise are wrong, at least about email that you read in your inbox. The other approach to message tracking is not to send the actual message in email, but rather some secure(ish) service on the web. But they have to send you a link to click on to see the message, and they can, of course, track your click on that link.

18 comments on “How Can Newsletter Senders Tell that I Haven’t Opened a Newsletter?”

  1. Something else to consider is that the e-mail is another form of SPAM. I’ve gotten several like this, along with those saying the person has been trying to contact me. Just hovering my mouse over the “from” element, I generally find the sending domain does not agree with what is displayed. An alternative way to check is by right-clicking the e-mail and selecting “view source.” However, it’s harder to find the “return” address.

    What I first noticed in the e-mail sample was it requested a response – either stop or continue. With those, I prefer “delete.” If it is legitimate, and I don’t want it, the company will most likely remove you from their database. If I do want it, I will go to the company’s website and sign up again. Either way, I won’t respond to this kind of e-mail.

  2. Oops! In the second paragraph, please change “the company will most likely remove you from their database” to “the company will most likely remove me from their database.”
    They wouldn’t remove someone else because I didn’t respond. (;

  3. There is another method, the one that I always use, that tells me *who* opened the email and the exact time stamp. I can also tell how many times each email has been opened by the same recipient in successive moments. As stated above, “open” doesn’t mean “read”, for the sake of clarity. Here it is the way I do: all my subscribers are registered into a mysql table. The program that dispatches the newsletter to subscribers injects a little piece of code personalized with the ID of the recipient in the mysql table. The code is an “img” tag the width of which is 1 pix, the height as well, and the “src” parameter being a CGI script in my server, being passed the ID after the typical “?” question mark. The image fails to display, but who will notice a 1×1 broken image ? Nonetheless the CGI script is being executed by the time the email is loaded into the SMTP client, it fetches the ID in the table, and marks everything I need. Currently I am also returning a real image as header of the newsletter. Actually, I also explore the maillog to check delivery failures caused by un-existent recipients, bad servers, spam complaints, etc.. That’s all in few words. I don’t know whether my approach is ethical, but it works.

    • It’s very common, because it’s the image tracking I mention in the article. And it’s easily blocked by people simply not displaying images.

  4. I been saving ur newletters since 12/5/11 when I started to subscribed. The reason that I saved them is many my friends think I am computer knowledge. I just print up all ur newletters and put into a folder then when my friends who r afarid to touch computer. I considered myself a novice but I do built my own computers. This is why my senior friends love me to fix their computer. I do get the computer working in a day or so. So please continue doing ur newletters. I love them. I do get about 200 to 300 emails a day so many times i put ur newletters in an external hard drive. then when I have time I print them up and put them in order with my table of contents. Again let me say thank u.

  5. I too, have gotten those emails that claim the people have been trying to contact me. This has only happened with my work email account, and I just delete them straightaway. I recently tried calling the phone number listed in one of those emails just to see what would happen. The number actually did belong to the company listed in said email, but when I asked to speak with the person who sent me the email I was told he was in a meeting. I opted to leave him a voicemail saying that I wanted to be removed from their list immediately. The guy has never gotten back to me.

  6. Since I use Windows Mail, and thus open my mail outside of my email provider’s site, can they still tell if I have opened it, or is that assumed when it is fetched by Windows Mail? Sometimes your newsletter comes through as spam, thus ends up in my junk mail folder, although that hasn’t happened recently.

    • If you have your email program set to automatically download (show) remote images or click to view images, then the sender can see if you’ve opened the email. Windows Mail and I believe most email programs nowadays have it set not to automatically download. So unless you’ve explicitly set Windows Mail to show remote pictures, the sender won’t be able to determine if you’ve opened their email. This also hold true for many web based email providers.

    • Also keep in mind that Leo is talking about “reliably” determining if you have opened it or not. No program can tell if you’ve actually read it! It can only sometimes tell that it’s been opened. In addition to the image tracking that Mark is talking about, clicking on links in the newsletter will also send signals back to the newsletter program. The whole reason for this kind of tracking in legitimate newsletters is to better serve you. It takes a lot of resources to send out newsletters, and legitimate writers don’t want to ever look like spam. They need to be able to see if their information is actually reaching people, and to clean out emails of people who don’t seem to really be reading it.

  7. Since my primary concern is that my provider will not see Leo’s newsletters as spam, it sounds as though I will have to be sure to download images, not just read the text. Good to know. Thank you Mark and Connie.

    • Good thinking Peter. And the reverse is also true. Don’t enable images on an email that you are unsure of… try to read it without the images before you decide if you want it. Enabling images basically sends a signal to the sender that you want it.

  8. If using a desktop client like Outlook or Thunderbird, if you have “remote content” enabled for a particular sender (e.g. askleo), what happens if you just click “mark as read” without actually opening the email?

    • Sure that could happen. Remember that the rule is to only click on links in emails that you totally trust. It’s the trust that counts.

  9. I would like to know about preview panels. If my mail client has mail in the inbox and I read them in the preview pane, does that show as “opened”? Or do I have to double click on it to open it?


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