Not that this is a hard trick, but a new tool on the market allows spammers to detect when your email has been read without your permission:
[It] sends out confirmations to the sender that the recipient has read an e-mail even when the recipient has disabled Return Receipts.
If your mail reader displays HTML, it will send a message back to [the sender] to indicate that your message has been read. In addition, it displays a message "The sender of this message requests confirmation when you read it. Click here to confirm." No need to click -- it has already been confirmed.
If you dislike this, you can set your mail reader to Text-only/no HTML allowed.
Another reason to set that e-mail to TEXT ONLY.
Posted by wasylik at May 31, 2002 10:35 AM