7 ms·

I believe gmail caches all the images so that leaves out a huge amount of the world maiboxes.

by skimmas 11y ago

moron4hire 11y ago
And regardless, I cannot support a project that I know will primarily be used to annoy the shit out of me in my own inbox.
- jeffjose 11y ago
  Dont dismiss something just because the current usecase doesnt suit you.
  - moron4hire 11y ago
    Actually, I implemented this very thing in C# on top of weather radar imagery back in 2006 (to be able to overlay real-time weather on a 3rd party mapping widget), so I've given the entire concept full consideration already.
jeffjose 11y ago
You're right. Google changed the way they did images a while back to prevent email image marketers who used to track when the user opened an email using a 1pixel transparent image downloads.
- hoorayimhelping 11y ago
  They changed about two years ago to run all images sent to a gmail address through their servers (and presumably store them). It specifically didn't effect marketing though. I was working in email marketing at the time and there was some temporary gnashing of teeth but this was not much more than a blip. https://blog.filippo.io/how-the-new-gmail-image-proxy-works-and-what-this-means-for-you/ https://blog.filippo.io/how-the-new-gmail-image-proxy-works-...
- andreyf 11y ago
  "1x1 transparent pixel" is called a "tracking pixel". Gmail still allows marketers to track when a user opens an email (even better than before, since it no longer asks users whether they want to load images). However, they proxy the request so that the tracking pixel host no longer gets the user's IP address or third party cookies.
  - nileshtrivedi 11y ago
    Where can I read more about this? Doesn't this help spammers? I thought I was safe if I disable auto-loading of images!
    - andrewguenther 11y ago
      Then don't open spam? I don't think a spam email has made it to my inbox in almost 5 years. Google's proxy protects your private data and only informs the sender that the email has been opened. I would hardly call that "unsafe"
    - ZoF 11y ago
      You're safe either way, but if you have autoloading disabled they still can't track that you've read until you load the images. The change is that clicking to load images is no longer the default [0] Do you get enough spam on your Gmail for this to be a worry point? Genuinely curious; I get roughly zero. [0]http://www.wired.com/2013/12/turn-gmail-auto-image-loading-off/ http://www.wired.com/2013/12/turn-gmail-auto-image-loading-o...
      - noja 11y ago
        > You're safe either way Eh? Before they used track-me.example.com/IDHERE and got blocked, now they use IDHERE.track-me.example.com and don't get blocked. Move the unique ID to DNS and Google will let it through.
        ZoF 11y ago
        I assumed by safe you meant something else. Yes if you load images they can track that you have opened the email. I fail to see how that is 'unsafe' though. It's expected functionality.
h1fra 11y ago
Few month ago I tested this, and it's seems they do not cache. Instead they are just using proxy to enable anonymous download of the image. But you never it any cache from google directly.
- paulddraper 11y ago
  They do cache at least sometimes, and they must for it to work. If I send you an image URL http://example.com/fH27cAw http://example.com/fH27cAw, and they URL is requested, you must have opened my email (unless something is requesting them regardless).
- duck 11y ago
  I actually wrote a little tool to help test this: https://github.com/kale/image-cache-logger https://github.com/kale/image-cache-logger You'll see that it in fact does get cached by Gmail, but only for a limited time.
yahelc 11y ago
From my testing, it seems like Gmail will cache via its proxy, but that cache respects the cache headers, so you can instruct Gmail how often to refresh the data. (That, and you can cache-bust on a per user basis using a unique identifier in the query string.)
erikvdven 11y ago
I have tested an image generated with this script in both Gmail and outlook clients and it works just fine. Else I wouldn't post it over here of course :)
gordjw 11y ago
It does work in gmail. Jetstar, an Australian air travel company, uses this technique (IIRC) and it works fine in gmail.

I believe gmail caches all the images so that leaves out a huge amount of the world maiboxes.

by skimmas 11y ago

I believe gmail caches all the images so that leaves out a huge amount of the world maiboxes.

And regardless, I cannot support a project that I know will primarily be used to annoy the shit out of me in my own inbox.

jeffjose 11y ago
Dont dismiss something just because the current usecase doesnt suit you.
- moron4hire 11y ago
  Actually, I implemented this very thing in C# on top of weather radar imagery back in 2006 (to be able to overlay real-time weather on a 3rd party mapping widget), so I've given the entire concept full consideration already.

jeffjose 11y ago

You're right. Google changed the way they did images a while back to prevent email image marketers who used to track when the user opened an email using a 1pixel transparent image downloads.

hoorayimhelping 11y ago
They changed about two years ago to run all images sent to a gmail address through their servers (and presumably store them). It specifically didn't effect marketing though. I was working in email marketing at the time and there was some temporary gnashing of teeth but this was not much more than a blip. https://blog.filippo.io/how-the-new-gmail-image-proxy-works-and-what-this-means-for-you/ https://blog.filippo.io/how-the-new-gmail-image-proxy-works-...
andreyf 11y ago
"1x1 transparent pixel" is called a "tracking pixel". Gmail still allows marketers to track when a user opens an email (even better than before, since it no longer asks users whether they want to load images). However, they proxy the request so that the tracking pixel host no longer gets the user's IP address or third party cookies.
- nileshtrivedi 11y ago
  Where can I read more about this? Doesn't this help spammers? I thought I was safe if I disable auto-loading of images!
  - andrewguenther 11y ago
    Then don't open spam? I don't think a spam email has made it to my inbox in almost 5 years. Google's proxy protects your private data and only informs the sender that the email has been opened. I would hardly call that "unsafe"
  - ZoF 11y ago
    You're safe either way, but if you have autoloading disabled they still can't track that you've read until you load the images. The change is that clicking to load images is no longer the default [0] Do you get enough spam on your Gmail for this to be a worry point? Genuinely curious; I get roughly zero. [0]http://www.wired.com/2013/12/turn-gmail-auto-image-loading-off/ http://www.wired.com/2013/12/turn-gmail-auto-image-loading-o...
    - noja 11y ago
      > You're safe either way Eh? Before they used track-me.example.com/IDHERE and got blocked, now they use IDHERE.track-me.example.com and don't get blocked. Move the unique ID to DNS and Google will let it through.
      - ZoF 11y ago
        I assumed by safe you meant something else. Yes if you load images they can track that you have opened the email. I fail to see how that is 'unsafe' though. It's expected functionality.

h1fra 11y ago

Few month ago I tested this, and it's seems they do not cache. Instead they are just using proxy to enable anonymous download of the image. But you never it any cache from google directly.

paulddraper 11y ago
They do cache at least sometimes, and they must for it to work. If I send you an image URL http://example.com/fH27cAw http://example.com/fH27cAw, and they URL is requested, you must have opened my email (unless something is requesting them regardless).
duck 11y ago
I actually wrote a little tool to help test this: https://github.com/kale/image-cache-logger https://github.com/kale/image-cache-logger You'll see that it in fact does get cached by Gmail, but only for a limited time.

yahelc 11y ago

From my testing, it seems like Gmail will cache via its proxy, but that cache respects the cache headers, so you can instruct Gmail how often to refresh the data. (That, and you can cache-bust on a per user basis using a unique identifier in the query string.)

erikvdven 11y ago

I have tested an image generated with this script in both Gmail and outlook clients and it works just fine. Else I wouldn't post it over here of course :)

gordjw 11y ago

It does work in gmail. Jetstar, an Australian air travel company, uses this technique (IIRC) and it works fine in gmail.