*In some cases, senders may be able to know whether an individual has opened a m...

		forgotAgain on Dec 12, 2013 \| parent \| context \| favorite \| on: Gmail blows up e-mail marketing by caching all ima... In some cases, senders may be able to know whether an individual has opened a message with unique image links. https://support.google.com/mail/answer/145919?p=display_imag...