> Now, an open question is if Google will make that request when the email is actually opened, which would allow marketers to determine if and when the email was read by the user, or if Google will make the request as soon as the email is received.
I reply to this question here. Sadly, a request is done each time and only when a user loads the image.
If google cached them as soon as they were received wouldn't they, in some cases, effectively perform a DoS attack on whatever was hosting the image? I.e. if a spammer sent out 1,000,000 emails w/ images they were hosting, they would immediately receive 1,000,000 requests for the image.
I think such a behavior is really easily spotted and filtered, if not already blocked by spam filters.
Google has the technology to do that, the question is whether they want to put in the investment of storage required to actually guarantee users privacy, of if they just want to spend the least amount they can get away with...
I reply to this question here. Sadly, a request is done each time and only when a user loads the image.
https://news.ycombinator.com/item?id=6898087
Which makes the Ars article even more wrong.