Dan Gillmor mentions a service called DidTheyReadIt and some of his concerns about it.
DidTheyReadIt and Civil Behavior
A company launching a new application claims it can tell senders of e-mail whether the recipient has opened it, and for how long (and even, in many cases, the location of the reader). "Creepy" doesn't begin to do justice to this concept. [Dan Gillmor]
I'd just heard of another service like this called Point of Mail. How do these services work? Easy, they embed a 1x1 image into your message when you send it. So if the person reading the email has a mail reader that supports html, it will grab that image from their site. This isn't anything new really. Spammers others doing mass emails have been doing this for ages. It's a way to get a rough idea of how many people read your messages (and can be handy for pruning email lists).
Dan Gillmor calls it creepy. I agree, but also have problems with how they are selling this. First off, it is easy to block. Just turn off html or image loading for your mail program. I did this ages ago because I just don't trust html based mail. Plus I don't always use Mail.app for reading mail. Sometimes I use pine, which doesn't support images at all. Yet there is nothing on their site about things like this. In the end, this ends up being a potentially very unreliable service for someone.
Oh, and one last thing about pointofmail.com. They have this nice open webmail gateway called sendnow.
pointofmail offers you a world's first web mail service that allows you to send an e-mail right away with no username and password needed. You can send e-mail from anywhere - using your e-mail as a reply address or even stay anonymous.
It's easy to use, free, fast, time-saving. You can send email from anywhere. No long-time logging with username and password. It is perfect when you are not near your computer.
Tell a friend about this exiting and revolutionary service and get confirmation when your recommendation was read.
I wonder how long till their SMTP servers are listed on RBL and similar places.