I've read in a post in Genbeta [es], about a "service" for e-mail senders called SpyPig. It basically boils down to sending a notification to the sender of an e-mail, when the recipient opens it. This way, the recipient can not say that she hasn't read it.
I will deal with two issues: moral and technological. Morally, I think this kind of things suck. I have received these e-mails asking for confirmation of having been read, and I never found appealing to answer. But at least you were asked politely. What these
pigs SpyPigs do is provide a sneaky way of doing it without the recipient knowing. Would you consider someone doing it on you a friend? Not me.
Now, technologically, the system is more than simple, and anyone with access to a web server could do it. The idea is that the sender writes the e-mail in HTML mode, and inserts a picture (can be a blank image) hosted at some SpyPig server. When the recipient opens the HTML message, the image is loaded from the server, and the logs of the server will reflect when the image was loaded, and hence the e-mail opened. When this happens, the server notifies the sender.
The bottom line of this story is that HTML IS BAD for e-mails. My e-mail readers never allow displaying HTML messages, and show me the source HTML code instead (of course, I can allow HTML, but why would I?). So this SpyPig thing will never work
for against me. And this SpyPig story is just one more reason not to allow displaying HTML in the messages you read. Of course, for the e-mails you send, consider sending them in plain text. Your recipients will be a bit happier.
For more tips on what NOT to do on web/e-mail issues, check the e-mail/web tips section in this blog.