its possible that he may know how many were opened.
by using HTML in the email to request an image, a 1x1 gif for example, from a server controlled by the spammer.
this image would be 'invisible' to the person who opens the email, but the spammer could possibly track the hits that the image recieves.
Slashdot Mirror
its possible that he may know how many were opened.
by using HTML in the email to request an image, a 1x1 gif for example, from a server controlled by the spammer.
this image would be 'invisible' to the person who opens the email, but the spammer could possibly track the hits that the image recieves.