How to find out when your sent mails are opened

Your online activity is ever more exposed, and even those who hide behind nicknames and anonymous avatars have begun to feel uncomfortable, what with, for instance, the controversial double-check on WhatsApp and premium services on social networks to find out who has visited your profile, among many other services tracking your digital activity. In the case of Sidekick, you’re looking at a Chrome extension that lets you find out the exact moment when someone opens your sent mails. The apocalypse has arrived!

The service is compatible with Gmail, Outlook, and Apple Mail, and the way it works is very simple: once you install and associate it with your account (using a social login or by manually adding a username/password), you’ll have options integrated into your email client to track each message such that you’ll get a pop-up window every time the recipient opens your sent message.

What’s the trick, then? Well, the system couldn’t be simpler, as the only thing the extension does is insert a small invisible image into the email that serves as an opener notification. When a user reads a message and their client automatically downloads the attached data, Sidekick will detect that the file with its unique identifier has been downloaded and then sends you a read receipt.

Effectively this means that as a general rule, unless the recipient worries about checking otherwise, he or she won’t realize that the email you’ve sent is being tracked. Outlook shows a small message alongside an email that highlights the embedded image, but Gmail swallows any attached image without notifying you of anything. The only way to avoid tracking from a Google account is by deactivating the automatic download of attached images as explained in this tutorial.

There were already similar services at the user level such as Mailtrack (as in the business world there have always been loads of tracking tools), but Sidekick takes the cake in terms of ease of use and extra features, such as the option to see the Twitter bio and timeline associated with the account you’re emailing to in your inbox. The free version of the tool has small limitations, such as a maximum of 200 monthly messages, but this should be more than enough for any standard user.