This Gmail trick reveals which companies sell your data

Have you ever registered with a new website and suddenly started receiving emails from companies and providers you’ve never heard of? If so, it’s highly likely that your data has been sold. Data is a valuable business these days and companies can make a lot of money selling your info to data brokers and other interested parties. This uninvited spam is certainly annoying, but don’t worry. Here we’ll show you how to stay one step ahead of spam and untrustworthy websites. And even if you don’t use Gmail, the following trick works with Outlook and iCloud as well.

How to find out who is selling your data

You might not know it yet, but your personal Gmail address has countless variations. By simply adding a “+” and a word or number in front of “@gmail.com” to your own mail address, you’ll be able to change your address, but all email sent to this new variation will still land in your mailbox as you’re used to. With this method, it’s now extremely easy to trace how and by whom your data has been passed around. Sounds too good to be true? Honestly, it’s really that simple, we’ll explain.

When you register with an online service, shop, or other website, you have to enter your email address. With this trick, instead of using your original Gmail address, add a “+” and the name of the provider or website.

So for example, instead of “dennis@gmail.com”, you can log in with “dennis+firma1@gmail.com”. You’ll continue to receive all emails from that provider or service to your normal mailbox, but you’ll also be able to identify exactly to whom they may have passed your data to.

So, if you’ve registered with “Firma1” and shortly afterwards, you receive spam emails from company 2, company 3, and company 4 with whom you have neither registered nor heard of, you can easily identify the culprit. If you open one of these spam emails in your inbox, you’ll see your mail address under “To”. If, in this case, it says “dennis+firma1@gmail.com,” then you know for sure that this service has sold your data to company 2, for example, which is now sending you spam messages.

To easily solve this, just unsubscribe and delete these spam emails from your inbox.

Data trading is not forbidden in principle

Yes, companies are allowed to sell certain data under strict conditions—email address trading is particularly popular. As a rule, you typically knowingly or unknowingly agree to your data being passed on to third parties by accepting the privacy policy of a service or website. Often users don’t even know this because the notice is hidden somewhere in the statement and most users don’t both reading it completely.

The above trick is therefore particularly well suited to finding out which service passes on your address data to third parties—whether with or without your knowing consent.

This article was translated from German to English, and originally appeared on pcwelt.de.