Google will start caching all remotely hosted images sent to Gmail users by default. The move will hinder e-mail marketers and other nosy senders by preventing them from seeing recipients’ personal information. Google servers request the Web address where the image is hosted only after a user opens the message. Google support pages also warn: “senders may be able to know whether an individual has opened a message with unique image links” Google says the new system is safer and more secure than other competitors.”]