Mobile: Newsletters are only sent if you logged in with your email address and have email notifications enabled. Tap ‘MORE’ on the bottom right of the home screen, and then tap ‘SETTINGS’.
You can change your email notification settings in the ‘EMAIL’ menu.
Desktop: Log in to the website, then hover the cursor over your username on the top right of the webpage. You can find ‘Account’ in the hover menu.
Once you select ‘Account’, you can change your email notification settings in the sections 'Service Emails' and 'Marketing Emails'