If you are getting Duolingo emails, but have not intended to create an account on Duolingo, someone else might have entered your email address when they made their account. Luckily you have full control over the account now and have the right to disable it by verifying that you are the email holder. Simply follow these steps to deactivate the fraudulent account:
1. Visit duolingo.com
2. Under "Login", select "forgot password" and follow the steps to send yourself a reset email.
3. Check your email and follow the link to reset your password.
4. Choose a new password and continue to Duolingo, signed in to the account.
6. If you know the person who used your email, you can stop there, log out, and create your own account with your email. The other person will then still be able to log in with their username if they know the new password (you would have to tell them what it is, since you changed it and they are not receiving emails from us anymore).
If you instead wish to remove the other person's account altogether, select "deactivate my account". Confirm.
When creating a Duolingo account, it is imperative to use your own email, not a made up one or someone else's. Creating an account under an email address that is not your own will make it impossible for you to recover a lost password and receive notifications, and also allow someone else to take control of the account and delete it. An account made with an email address other than your own risks deletion at any time, without previous notice.