Often, fraudsters send suspicious emails and try to perform spoofing or phishing activities when recipients open them and download the images in them. Taking this into consideration, mailbox service providers will block auto-download of images so that the mailbox owner is not compromised.

 

In the recipient mailbox, if the auto-download image option is disabled, none of the images—including the one-pixel tracking image added to track the open rate—will get downloaded. In these situations, we'll be able to track open rates only when the recipients manually download the image.