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=

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_images&rd=1 https://support.google.com/mail/answer/145919?p=display_imag...