How to stop your emails from being tracked on iOS.
If someone sends you an email with a 1×1 pixel image, they will be able to know when, where and from what device you read this message, and will also receive your IP address.
To prevent this, you need:
1. Go to "Settings", click on "Mail".
2. Disable "Load Remote Images".
Now, when you open any letter, images will not be loaded automatically, and to download an image, you need to click on "Load all images" at the top.