They're just acting as an email client. Alice sends email to Bob, Bob is granted rights to fetch and view images. Bob uses gmail, so he passes the rights onto google to do part of that serverside.
He certainly passed on a significant portion of the rights or that server wouldn't be authorized to receive and permanently store the emails in the first place.
Do you think copyright law disallows running your desktop in the cloud?
I came here to say basically the same thing, so I'm going to chime in in support of what you're saying. If I'm a marketer and I send an email with a link to the image, and Google caches it in order to resend it for their own purposes (even if that's to shield their users from spam), how is that not a copyright violation? In this case, caching is no different than copying; and the kind of caching Google is doing in this instance is different than the caching an individual does via his browser, since the individual downloaded the image in the original instance.
I see where you're coming from, and IANAL etc, but this surely must be a solved problem? For at least the last 15 years (longer?) we've had web mail where mail you send doesn't go directly to the user but via some other servers. If there is an actual issue here it's going to be a hell of a legal battle.
