Abstract
In 2017 , readers used their iPhone to browse the email newsletters of compan y X and found that it displayed a product image of com pany Y. The iPhone's default mailer registers the received inline image in the HTML mail along with its cid in the cache. On the other hand, the cid of the inline images in the HTML mail delivered by mobyle t were
not unique. Therefore, (1) When opening an HTML mail of company Y delivered by the system using mobylet on iPhone, the inline image is registered in the cache. (2) Another system utilizing mobylet by company X sends an image having the same cid as c ompany Y's inline image to the same iPhone in an HTML mail. (3) When opening the mail delivered by company X on the iPhone, Company X's HTML mail displays the inline image of Company Y registeredin the cache with the same cid, instead of the inline image of company X.
