I'd like to try a viral email campaign to distribute a message. But I'd also like to track how the mail is being distributed. I am aware that you can use the google analytics url builder to specifically track when people are clicking hyperlinks in the mail to go to your site. But can you also track the fact that the mail is simply opened on a user's machine, so we can see if the distribution is still taking place even if people don't click the links? Maybe insert an image from the website into the email sig and see how often this is downloaded? Any suggestions?
I don't think that's possible with GA. I think you should get an emailing software to manage that. There are a lot of those great ones out there.