Why Remote Images Can Be Risky in Email

An image can be a network request

A tiny invisible image can serve the same remote-loading purpose as a large banner, so visual size is not a reliable signal of whether tracking is involved.

A temporary inbox changes how long you keep the address, not the basic rules for trusting a message. Sender, destination, timing and the action you actually initiated still matter.

Some email content contacts another server when it loads

Remote images are not just decoration. Loading one can make a request to an outside server and may reveal that the message was opened. Blocking that content by default in a suspicious message preserves more control until you decide the context is trustworthy enough.