Here is a suggestion I just sent the Android Gmail team:
If an email sender has been previously approved to display images, the images should be loaded when the email is downloaded to my phone.
Right now the images are loaded when the email is viewed for the first time. This means I have to wait for the images to download and depending on my internet connection that could be a while. If I’m checking my email where there is no service (on subways, elevators, about 1/2 of Berkeley CA) the experience totally sucks.
If images are pre-downloaded, it will break “web bug” functionality built into email images. But web bugs have never been a web standard, just a clever, if unreliable hack at gaining metrics. If you’re totally excited about it, you could build a new web standard for when web bugs get viewed. Also, nowadays, if a user cares enough to have emails go to their inbox (and not unsubscribing, or marking it as spam), they are probably interested in reading the email, so web bugs aren’t that important any more.
Thanks for your consideration!