23 ms·
Spy pixels in emails 'have become endemic'
- deleted 6y ago[deleted]
- anothernewdude 6y agoWho the fuck views images in email?
- pfundstein 6y agoI can't think of any email clients that automatically download external images by default. The article seems to be over-blowing the issue a bit.
- funman7 6y agoI think at one point Gmail was wanting to do that then didn’t do that.
- xnx 6y agoGmail does. This is great for privacy because it destroys the usefulness of the tracking pixel to the marketer.
- alaties 6y agoEh... Not really... It's pretty easy to generate a unique image url per customer and use that to determine whether a customer opened the mail or not and it's about the same cost as a traditional tracking pixel, complexity-wise.
- ralph84 6y agoIndeed, the three email tracking services I'm familiar with (HubSpot, Yesware, and Outreach) all generate unique URLs per recipient. The only information you don't get for Gmail clients is location, but you get the most valuable info which is if/when/how many times the email is opened.
- neeleshs 6y agoI remember reading that gmail caches these images, rendering the how-many-times useless.
- alaties 6y agoGMail absolutely caches images. The cache is primarily for performant delivery of data over mobile networks though and reduced load of repeat same-day viewing, and less for privacy. While their cache is large, it's not infinite. If what you're interested in is whether a customer engages with an email multiple times over a few days, you'll likely get the pixel hits to confirm it over that time period. Of course, as you imply, you wouldn't be able to collect how many times an hour a single customer has viewed an email sent to them.
- godmode2019 6y agoI have tested this and the cache expires pretty quickly. From memory 10min -30. I thought that was fine because its around about one hit per session. You get enough good information. The IP address would be even better however.
- Mulpze15 6y agoDoes Gmail download by default, whether you open the email or not?
- wahern 6y agoGMail displays them. It uses a proxy for downloading, but I don't think that matters unless they're preloading all images unconditionally upon server-side receipt of the message. Apple's macOS Mail.app client displays external images by default, as does their iOS app.
- sep_field 6y agoon iOS: turn that off with Settings > Mail > Load remote images
- officialjunk 6y agorecently i am seeing certain images still loaded, whereas in the past none loaded. i haven’t investigated what is different about these images yet, though. anyone else observe similar?
- gtufano 6y agoYou can embed the image inside the actual multi-part message, and it will be shown without accessing network. It is usually used for logos, signatures and the such and, afaik, can't be used for tracking mail opening.
- m_eiman 6y agoCould be images with image data included in the email, that don't need to load remotely.
- musicale 6y agoI'm somewhat disappointed that Apple doesn't offer better default privacy for Mail. Perhaps they can't figure out a good solution to differentiate between benign images and tracking images; it does seem like it would be nearly impossible to do so, but I wouldn't mind a) blocking external images by default, b) per-sender/recipient settings, and c) clearly displaying "invisible" images and warning about them. Perhaps someone has some better ideas on how to fight this scourge? I tend to think that the only practical solution is to block them entirely, but then malicious senders will send URLs that say "click here to view message." Maybe HTML email wasn't such a great idea.
- gorgoiler 6y agoiOS mail, alas. I just found it turned on. I forgot to disable it again after my annual OPSEC-cosplay device-wipe.
- im3w1l 6y agoI've seen this expression here a few times and I don't mean to single you out, but arghhh! The cos in cosplay stands for costume. Roleplay! Unless you are putting on a literal white hat I suppose, that would be cool.
- Griffinsauce 6y agoIt's figurative? The point is that they're pretending to be something they're not.
- kibibyte 6y agoMany third-party mobile email clients I've used in the past never gave you the option of disabling image loading, though some of them finally added the feature after many years (e.g. Outlook).
- deleted 6y ago[deleted]
- deleted 6y ago[deleted]
- m463 6y agoApple mail will load them if you forward an email, even if you have remote images turned off. (last I checked)
- bennyelv 6y agoNot only that, but the way the article came about seems to be a bit strange. Apparently the BBC asked Hey to some analysis on their emails, and have written what appears to be a publicity piece for them on the result. Did you know that Hey allows you to block tracking pixels for the low price of $99/year? Now you do! Not the kind of thing I'd expect to see from the publicly funded BBC.
- grey_earthling 6y agoThe BBC has form on this. They periodically publish news articles reporting that a person's life was saved by the app What3Words, without mentioning the existence of similar proprietary and open systems. See for example: => https://www.bbc.co.uk/news/uk-england-stoke-staffordshire-55921168 https://www.bbc.co.uk/news/uk-england-stoke-staffordshire-55... 2021-02-03 What3words: Stafford women rescued from flooded river after using app => https://www.bbc.co.uk/news/technology-49754820 https://www.bbc.co.uk/news/technology-49754820 2019-09-20 What3words: 'Life-saving app' divides opinion => https://www.bbc.co.uk/news/uk-england-49319760 https://www.bbc.co.uk/news/uk-england-49319760 2019-08-15 What3words: The app that can save your life (Yes, that's the headline they used.) => https://www.bbc.co.uk/news/technology-47705912 https://www.bbc.co.uk/news/technology-47705912 2019-03-26 Three-unique-words 'map' used to rescue mother and child => https://www.bbc.co.uk/news/technology-40935774 https://www.bbc.co.uk/news/technology-40935774 2017-08-30 TEDGlobal: Three words that give people an address => https://www.bbc.co.uk/news/business-32444811 https://www.bbc.co.uk/news/business-32444811 2015-04-29 Giving everyone in the world an address
- bennyelv 6y agoThey're even using the company's marketing materials for the images in the articles. If I had the time or energy, I'd complain about all of the above.
- deleted 6y ago[deleted]
- eqvinox 6y agoMy email client doesn't even have the capability to display images or download anything... (It's mutt.)
- eli 6y agoALL of the top 10 email clients download external images by default.
- iamacyborg 6y agoI work in email marketing so this is a topic that's pretty near and dear to my heart. I actually wrote about the issue the industry has with tracking on my blog a while ago, and have spoken on a panel and a podcast on the subject too. There was some great discussion on the blog past when I posted it here https://news.ycombinator.com/item?id=21024926 https://news.ycombinator.com/item?id=21024926
- 2Gkashmiri 6y agohttps://mailtrack.io/en/ https://mailtrack.io/en/ yeah. webmails open images by default so companies like these are charging top dollar for the priveldge
- dschuetz 6y agoRoundcube doesn't.
- 2Gkashmiri 6y agogood. i have recently switched to MIAB and the legacy has to be continued in parallel for some time but this is one of the benefits. nice
- quijoteuniv 6y agoAnyone knows if pihole blocks those addresses?
- nitrohorse 6y agoPotentially, depending on your Pi-hole’s blocklists. For reference you could check against these popular spy pixel lists: https://github.com/apparition47/MailTrackerBlocker/blob/main/Source/MTBBlockedMessage.m#L72 https://github.com/apparition47/MailTrackerBlocker/blob/main... https://gist.github.com/dhh/360f4dc7ddbce786f8e82b97cdad9d20 https://gist.github.com/dhh/360f4dc7ddbce786f8e82b97cdad9d20 https://gist.github.com/leggett/8c2ab9735037cb66c218fdbe898ddf68 https://gist.github.com/leggett/8c2ab9735037cb66c218fdbe898d...
- quijoteuniv 6y agoThanks for replying to the question i meant to ask! I will check those blocklist!
- iloveparis 6y agoThese lists seem great but aren’t in a pihole-compatible adlist format. Did you mean that one could take these and create pi-hole lists?
- jack_riminton 6y agoHey.com is a good solution for automatically stopping emails that do this
- jack_riminton 6y agoLol at the downvotes. I don't work for them!
- gspr 6y agoIf I were to guess, the downvotes stem from the suggestion that changing one's email provider to a specific other one is supposed to be a reasonable way to combat tracking pixels. It's kinda like suggesting moving to fix a leaky pipe.
- jack_riminton 6y agoNo I wouldn't suggest that. I mainly moved because of the other features But the pressure from Hey is persuading some companies to stop doing it https://twitter.com/dhh/status/1359437390763483141?s=20 https://twitter.com/dhh/status/1359437390763483141?s=20 So it's not avoiding the root cause entirely
- j-james 6y agoWhat's the history behind allowing external images in emails? Was it a size limitation? HTML emails already use only a subset of HTML, so I don't understand why it wasn't trimmed down more to only allow images as data URLs or encoded in Base64.
- JimDabell 6y agoConsider how many HTML emails the average person receives. Now add 2MB+ [0] for all the images that are attached to each of those emails. Then add the 33% overhead for Base64 encoding them. It adds up quickly. Before Gmail came along and drastically increased mailbox sizes, having images attached to every HTML email would quickly overwhelm typical mailboxes. [0] https://www.litmus.com/blog/qa-with-mailcharts-on-email-file-size/ https://www.litmus.com/blog/qa-with-mailcharts-on-email-file...
- peteri 6y agoI suspect partly size but mostly tracking. Images in email have been around since 1992 (RFC341 Multipurpose Internet Mail Extensions https://tools.ietf.org/html/rfc1341 https://tools.ietf.org/html/rfc1341 ) and I don't remember when downloadable images got added to "text/richtext" but the concept of downloadable content is already there in section 7.
- eric4smith 6y agoFor legitimate email marketers these pixels are important to have because: 1. Helps to prune users who never open emails thus giving you a smaller more engaged list. 2. Helps to see if the content they are sending to users is leading to engagement so they can send better emails next time. Yes, yes I know. Why even send emails in the first place. All email marketing is not evil. But legitimate marketers have businesses to run in the real world and without these little pixels they would be sending un-targeted and mostly useless marketing messages to legitimate subscribers.
- mattmanser 6y agoThe attitude you have that it's your right to know whether someone opened an email is the problem. How you casually mention spying in to someone else's home and watching their actions as if it's perfectly normal is really creepy. There's nothing 'legitimate' about those marketers, they're exactly the problem.
- Nextgrid 6y ago"engagement" is a proxy for "wasting their time". That's not something your recipients benefit from.
- gspr 6y agoAll of that is irrelevant. Someone wants to send me a message. That message may or may not be legitimate. There is nothing in the contract of messaging someone by email that says that I have to reply in any way, be it with an answer or with tracking information. There is in particular nothing that says that my email-reading software should go behind my back and send information back to the sender of the message. If it did that, I'd be furious. What you are suggesting does not fit in the medium of email, independent of the legitimacy or intentions of the sender.
- aenario 6y agoAdd buttons in your email - "I want to know more" - "It's too expensive" - "Leave me alone" All open rate tells you is that your subject line was click-baity but the user have no interest in your content
- vtd 6y agoThe same tracking functionality can be attached to logos in the email without raising any suspicion.
- OJFord 6y agoWho blocks (attempts to block) tracking pixels but allows other remote images? How many clients even offer that?
- iamacyborg 6y agoIt can be attached to any remotely accessed image. IIRC, Facebook were using audio tags at one point for email tracking.
- legitster 6y agoThis goes beyond nefarious marketing purposes - I know lots of people who have started to use open trackers in their personal emails! In a certain way, for people who are now very accustomed to read receipts, it's a way of adding a modern feature to a legacy product.
- kjakm 6y agoRead receipts are generally something the recipient agrees to and are visible to both parties or none. A tracking pixel is secretive and the recipient gets no benefit or choice. Very different implementations.
- tibu 6y agoIs it a privacy concern if somebody sent me an email with my consent and wants to know whether I read it or is it just creepy if they start telling me That they saw I read the email?
- relix 6y agoIf you're running a mail newsletter, this tracking is pretty important. You're supposed to stop sending emails to someone who's not interacting with them, or you get an extra point towards being flagged as spam. Since people are already weary of clicking the unsubscribe link and instead casually mark everything as spam, every little bit towards keeping your reputation counts. It's a damned if you do, damned if you don't situation. This is the reason why I had to implement a tracking pixel on https://hndigest.com https://hndigest.com Tangentially related anecdote: I also had to implement redirects instead of direct linking to the stories: At one point a URL with the .tk TLD was at the top of HN, and as soon as I sent out the first email with that story in it, my email sending service immediately flagged my account as a spammer and blocked all my sending, because the .tk domain was such a red flag. Since then I redirect all stories through my own domain, to avoid any other TLD red-flags from crippling the service. It's difficult running a legit DIY newsletter, every party involved is super suspicious and one wrong move or mistake can end it all. Edit: A lot of people are wondering about why I think people press the spam button instead of unsubscribe, so let me elaborate a little more. HNDigest uses double opt-in (you receive a confirmation email which you need to click on before you're subscribed), listens to all feedback loops, has an instant unsubscribe button. We never spam or send emails that weren't requested by the user. By all accounts, it's a legit newsletter and I try to be as above board as possible. Yet 30% of all unsubscribes happen because someone has marked the email as spam. I know this because this generates a notification on the feedback loop, and then I immediately stop sending of course. These are the facts. So, assuming HNdigest is not actually spamming (which is something I do believe), 1 out of 3 people click the spam button either by accident, or to unsubscribe.
- fraudsyndrome 6y ago> Since people are already weary of clicking the unsubscribe link Can you please elaborate on this? Do you mean people intentionally avoid this because it leads to the advertisers marking that as "read" and therefore a live user? Asking because I recently purged my old emails which had thousands of emails, they obviously never stopped sending even with zero interaction. But my method was to click the unsubscribe link which I was afraid might give them more information about them and doing the opposite of what I wanted. I know some didn't even respect the unsubscribe, I took note of which ones I explicitly clicked and they're still sending spam to me.
- phreeza 6y agoI used to be under the impression that the Gmail proxy protects you from this, but then I learned (on a different HN thread) that this is only partially true. It protects you from the sender harvesting the user agent etc, but it still only fetches the images when you open the email, so still leaks information. This promoted me to disable automatic image loading in gmail.
- pmlnr 6y agoUse plain text view by default.
- d--b 6y agoFor anyone's benefit: this is not what "endemic" means.
- tempodox 6y agoendemic (adjective): regularly found among particular people or in a certain area. I'd say tracking pixels are regularly found in the area of email.
- wastholm 6y agoWhat irks me is when email newsletters that I'm willfully subscribed to (the Economist comes to mind) inform me that "since I haven't been interacting" my subscription will be terminated. I have too been "interacting" (or as I call it, "reading") but my email client, very sensibly, doesn't load external resources, like pictures, willy nilly.
- btgeekboy 6y agoIt's quite the juxtaposition seeing your post right next to https://news.ycombinator.com/item?id=26163842 https://news.ycombinator.com/item?id=26163842
- wastholm 6y agoAs someone with a daily email "newsletter" of my own [1], I am aware of (many of) the vagaries of spam filters. I use plain text only, though, so I couldn't use tracking pixels even if I wanted to. I do unsubscribe users if messages start bouncing but I have no way of knowing if they get silently dropped or spamfoldered. As someone who subscribes to lots of newsletters, the "interact or we will auto-unsubscribe you" thing still annoys me. [1]: https://www.aphorismsgalore.com/daily https://www.aphorismsgalore.com/daily
- jedimastert 6y ago> I do unsubscribe users if messages start bouncing but I have no way of knowing if they get silently dropped or spamfoldered. IF you get spamfoldered by enough people the provider will just start sending to the spam folder for everyone. Your newsletter is now useless
- anewone 6y agoAnd on top of that, some mail providers like Gmail won't even tell you this is happening. I understand why they don't but it's really difficult if you're a small time newsletter trying to get off the ground.
- 6y ago
- aero-glide2 6y agoProtonMail disables this by default. You have to click on "load" to enable remote content.
- tirpen 6y agoSo does Thunderbird.
- deleted 6y ago[deleted]
- jeroenhd 6y agoI wonder if these are even legal I'd er the GDPR. There's no opt-in for these tracking pixels yet they track user behaviour through a third party that knows personally identifiable information (an email address). The BBC article says this shouldn't be happening, but with the UK abandoning the EU I don't know how close to the GDPR the UK is willing to keep their laws. I hope some data processing agency will look into these tracking companies. Without an optional opt-in at sign-up, emails should never include these pixels.
- jjav 6y agoThis is why (not the only why, but an important one) I only read email with mutt.
- soheil 6y agoHey [1] blocks tracking pixels but is smart enough to still show images. https://hey.com https://hey.com
- iamacyborg 6y agoIf it's allowing images it's allowing tracking, unfortunately.
- o_m 6y agoHey's solution is pretty smart. Their servers open the image and cache it as soon as the email goes through their servers. That way the pixel data is garbage. If you open the email multiple times it gets the images from Hey's cache.
- soheil 6y agoInterestingly enough this is also what gmail does, however, then they notify the origin server on every email open even though they're serving the cached version, pure evil.
- Tepix 6y agoThat seems like it's not going to be possible in the long run. You can turn the company logo into a tracking pixel.
- mike-cardwell 6y agoIf you want to test if your email client is loading tracking pixels, or a variety of other techniques to track your message reading, check out out https://www.emailprivacytester.com https://www.emailprivacytester.com
- indeyets 6y agoA lot of comments here, that tracking pixels are needed to check if recipient is actually getting messages. But couldn't you do the same via click-tracking? After all, email marketing is almost always about getting clicks
- petercooper 6y agoYes. Click tracking is generally considered acceptable even by people who are dead against open rate tracking (DHH comes to mind). If your email is of a nature where the occasional outward click is expected and you wanted to clean the list of anyone who fails to click whatsoever, click tracking is an option.
- holstvoogd 6y agoFor anyone using pixels: Under the GPDR tracking pixels require explicit consent as they monitor user behaviour. This _cannot_ be covered with any implicit forms of consent like 'you subscribed to the newsletter'.
- codethief 6y agoI wish we'd have lawers sending out cease-and-desist letters to companies that use tracking pixels – just like back in the 2000s there were thousands of lawers that sent us letters when we used KaZaA…
- veeti 6y agoHow many complaints have you filed with your local data protection authority about this?
- deleted 6y ago[deleted]
- dsm9000 6y agoI still read/triage my email with a text only client in a terminal. Much faster for me to consume when the font, spacing and layout is consistent. The bonus is that it also avoids sending good and bad telemetry back to other parties.
- jonathanstrange 6y agoI'm using claws-mail in a way that defaults to plaintext email only. I can load the html mail, but rarely do so. When a mail does not show the content in plaintext I usually throw it away. The reason is pragmatic, by the way. HTML mails take longer to read, and I really don't need some crappy graphics or web design when scanning through my inbox.
- lebaux 6y agoThe article is an ad for Hey email, not much else.
- tabs_masterrace 6y agoFew years back when awareness about email tracking wasn't so common, I noticed often I after I looked at one of those recruiter spam emails, they'd call my phone 5 minutes later. Just downright creepy stuff. Leaned to disable "Load remote content" since then. Unfortunately it's on by default and many less technical users probably have no idea what's happening.
- petercooper 6y agoI'd love to know which PR agency Basecamp uses. They have really had some fantastically timed mainstream press over a number of issues (most notably, the Apple 30% cut one) and I can't help but think there is a very smart agency pulling it off.
- tim-- 6y agoI'm sure having 400,000 twitter followers and being known as the creator of Basecamp/Ruby on Rails definitely helps. https://twitter.com/dhh https://twitter.com/dhh
- donatj 6y agoI recently received an email that telling me they were unsubscribing me from their list because they had seen I had not opened the last X number of emails. On the one hand, that's pretty courteous, on the other hand kinda unnerving.
- korse 6y agoHow do tracking pixels handle a mailbox setting that doesn't load images by default?
- meamin 6y agoThey don't. I believe using this setting it is a good way to prevent tracking by pixel. In addition, I think enforcing plain text emails would disable any client side tracking events. EDIT: Well it looks like that setting in Thundebird prevents any remote connections. Not just pixels, so that be good enough. However emails often have a text back up that is going to be better formatted then a hampered html email. EDIT: To prefer plain text in Thunderbird it is View -> Message Body As -> Plain Text
- jessriedel 6y agoDo any email clients do the opposite and just download and save all images by default? This would allow your email client to render every email as intended, but would give no useful information to the tracking service.
- amluto 6y agoThe major email clients could easily fix this. Instead of having choices to not display images and display images, the choices should be no images, show embedded images, and show remote images. The latter should come with a big privacy warning and require dismissing the warning for every single email. Problem solved.
- leesalminen 6y agoThat sounds like terrible UX. Users will automatically click on the button so that they can see their email. Nobody reads pop ups.
- amluto 6y agoIf it’s sufficiently annoying, people won’t click it. It could work a bit like browser insecure warnings work now. Or perhaps users could be required to click remote media to view it. Most users won’t care, so they won’t click it.
- smoldesu 6y agoMost privacy-oriented email clients already do this, and it works fine in my opinion. I can read most important emails without extra formatting.
- bootlooped 6y agoProblem is that a core part of the content of many emails is the images. Many emails I get are useless without them, I get the subject to guess what it's about, and if I only have the text to go on it becomes a mystery. I get emails from Nintendo or Steam when a game in my wishlist goes on sale. I think they just show an image of the game in question. Maybe the game name is in the raw source, but it is equally likely the only thing I'd find in there is some internal game ID that means nothing to me. The way to solve it is for the email provider to download the images for you, not when you open the email, but as soon as they receive it, and then display the images from their local cache. That way your IP never hits the pixel's home server, and you can see the email as it was intended to be seen.
- fireball_blaze 6y agoThe article is a strange advertorial for Hey.com from the BBC. Why didn't they interview anyone from the large email providers to get their opinion and learn what they are doing to protect users? Hey.com is a tiny blip in the email universe.
- himynameisdave 6y ago"Do not load remote images" boom, done.
- deleted 6y ago[deleted]
- CptFribble 6y agoThis seems like thinly veiled marketing for Hey? "There's a Big Scary Problem you probably didn't know about, according to the founder of a service that solves that problem." [Image of what it looks like when the Big Scary Problem is solved by the service.] [Flattering image of the service founder, and a reference to the service as 'premium.']
- iso1631 6y agoThat was my original thought this morning, such a blatant press release. A "ready to go" article to the journalist to do the work for the day and get on with something else, common practice. However note the intro "according to a messaging service that analysed its traffic at the BBC's request."
- mattnewton 6y agoCame here to say this, and reference the pg article about “the submarine”. This reads like it was written by a PR firm. As a Hey user, this is the least salient thing about the service to me, but maybe they think it is the best way to compete with Gmail?
- networkimprov 6y agoYes, it's clearly a puff piece. Can I bribe a BBC editor to get them to write about mnm & TMTP? :-) It also prevents spy-pixels, and phishing, and provides unsubscribe (from threads, or senders, or whole sites). mnm, an open source project to replace email & SMTP: https://mnmnotmail.org https://mnmnotmail.org https://twitter.com/mnmnotmail https://twitter.com/mnmnotmail
- cwhiz 6y agoUnfortunately, Hey is only decent at catching tracking pixels. I have my mail apps set to not load remote content, and it is obvious when an email tries to load some tracking garbage. With Hey there is no option to block remote content, but they attempt to prevent tracking and let you know, quite proudly, when they have. However, during my (evaluation of Hey I've noticed many, MANY, instances where the same email in Hey won't show any tracking pixels, but my mail app has obviously refused to load them. I'm unimpressed with Hey's ability to prevent tracking.
- tus89 6y agoCan someone explain how a tracking pixel works? How is it different to simply a unique image href url for each client? Why does the image itself need to be different?
- ratww 6y ago> How is it different to simply a unique image href url for each client This is exactly how it works. The image itself doesn't need to be different. Normally it's a 1x1 transparent gif.
- Ombudsman 6y agoIf I understand this correctly, the unassuming image/jpeg/png/gif/pixel is embedded in the email, it's the same color as the background so the user wont notice it. The image itself which has a unique link for each recipient, is hosted in the senders servers, so when they receive the request for the image, they read the HTTP headers for information such as IP address for location, depending on how many requests they get they can count the number of times the email is opened etc
- tus89 6y agoRight. I somehow interpreted it to mean a pixel in an existing image on the email, not some random pixel image. Which makes me wonder why they don't just embed normal images that the user would see, but add something to the href that the server can interpret as a unique id. Either way, email clients that block images will break the technique.
- anewone 6y agoThere are certainly companies doing this already. The only advantage of a tracking pixel is if your email content doesn't have any images already. And I guess it sounds scarier for a headline.
- iso1631 6y agoNone of my mail clients (including OWA and other web based ones) load external images -- I'm surprised this is such a problem.
- kelnos 6y agoDo people actually habitually load images in emails where they don't recognize the sender or don't have a specific reason to? IIRC the GMail default has forever been to not load images without an extra click. The only time I ever click that is if it's a personal email from someone I actually know, and I actually want to see the images.
- dwighttk 6y agoGreat. I only load images when I desire, and only rarely.
- Diesel555 6y ago> Emails pixels can be used to log: > if and when an email is opened how many times it is opened Can someone explain to me how these work? Do you load remote content from a server so it knows that the email was opened? Does it re-download this image every time it is opened?
- anewone 6y agoGenerally images in emails are linked, and not actually sent with the email. So any time the email is opened, the email client makes a request to the image host, and this request can contain a unique identifier for the recipient. Some email services will cache the images for a period of time but in many cases it will perform a fresh request each time the email is opened.
- smoyer 6y agoUse a text-only email client ... it won't attempt to load the tracking pixel.