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So this won't work with emails coming from Gmail (and probably other providers) since these services cache these images on their server as soon as they receive
by hota_mazi 10y ago
So this won't work with emails coming from Gmail (and probably other providers) since these services cache these images on their server as soon as they receive them (and not when recipients open them) precisely to defeat this kind of tracking.
And of course, a lot of email clients only open such images on demand anyway.
- iancarroll 10y agoI don't believe this is correct. Gmail will only request an image to proxy once you've opened the email, according to MailChimp, so this would only prevent tracking multiple opens. http://blog.mailchimp.com/how-gmails-image-caching-affects-open-tracking/ http://blog.mailchimp.com/how-gmails-image-caching-affects-o...
- hota_mazi 10y agoIt's actually hard to track down exactly when these images are cached. I don't really trust MailChimp to be truthful about this but I also can't find any specific from Google themselves about whether that caching happens when their SMTP receives the email or when the user actually opens the message. Since Google's goal with this was clearly to defeat tracking, I would strongly expect the former, but I can't back this up.