Imagine that inside your mailbox — the one for snail mail, that is — a camera is monitoring which flyers you read and which ones you chuck out without a second glance. You might never have pondered it, but e-mail provides the creators of spam and ad mailings that very ability.
Throughout its existence, e-mail has evolved: from simple text to eye-catching messages incorporating all kinds of fonts, styles, and embedded images. In terms of capabilities, e-mails are now similar to Web pages, meaning that senders can embed elements in messages to track what’s happening in your mailbox.
How does e-mail tracking work?
Researchers from Princeton University analyzed about 1,000 ad mailings. They found that 70% of the messages contained ad trackers — automatically downloading elements such as invisible images that not only inform the sender when and how many times you opened the message, but also transmit personal data (for example, your e-mail address) in the query string. What’s more, the tracking domain query reveals your IP address, from which your approximate location can be determined.
Such technologies allow the creators of ad mailings to target their messages more effectively. For example, tracking is extremely useful for so-called A/B testing, which helps determine which message topics and types (say, with or without emojis) people are more likely to click. On top of that, ad trackers can store browser cookies so as to “recognize” you on other sites that are not even related to the mailing topic.
That way, the advertising network gets more information about your interests, and they can sell that information to advertisers. For example, if you opened a message about discounts on sneakers, sports footwear ads could start hounding you online.
How to protect yourself
If you use the Gmail webmail client, you’re ever so slightly in luck. This provider (and possibly some others as well) download all images from the message to their servers before passing them to you. That means advertising networks can’t store cookies in your browser or learn your IP address — unless they pay Google for the information.
Here are a few tips to help protect against being tracked through your e-mail:
- Disable automatic downloading of images in the mail client, and download images only from trusted senders.
- If imageless messages seem too boring, use a tool to block tracking, such as Private Browsing in Kaspersky Internet Security.
- Using a VPN will help conceal your real IP address from advertisers.