On Wed, 2009-11-18 at 09:04 -0500, Andrew Ballard wrote: > On Wed, Nov 18, 2009 at 4:30 AM, Angus Mann <angus@xxxxxxxxxxxxx> wrote: > > 1. Is possible. Google the term web-bug. Be prepared that it will only work > > if the recipient has a HTML enabled email reader AND allows downloading of > > images. Be prepared also that every time the email (including forwarded > > emails) are viewed your server gets a hit. Might equal alot of hits. Just > > embed an image with a unique filename (tiny or invisible if you want) in the > > email and make it's source your server. Then track requests for that image. > > > > In various environments, I use G-mail's web service, Thunderbird and > Groupwise, and all 3 disable images by default specifically to prevent > exactly what you are suggesting. I suspect many other mail clients do > the same, not to mention a lot of people use text-only e-mail clients > that cannot display images. > > Most people I know don't want to be tracked like this, and if they > find you are doing it they will simply remove themselves from your > mailing list and/or direct the messages to the trash. > > > Andrew > I think that people removing themselves from mailing lists is a little extreme. I wouldn't remove myself just because I thought I was being tracked. There is another way to track reading of emails though. Microsoft Outlook created something called read receipts. Users still have to accept the read receipt to be sent to the sender, so it might be a slightly more obtrusive way of finding out who read what, and afaik, it only works on the first read of an email. I don't know exactly how they are formed, but I believe it is some form of special attachment to the email that is recognised by some email clients. Thanks, Ash http://www.ashleysheridan.co.uk