I keep getting (more than once a week) an email supposedly from Norton asking, "Is your email for sale on the dark web?"
Is this a real message from Norton? I suspect it since it just keeps coming.
Norton has a list of e-mail addresses they use to contact customers in the support article Make sure that the Norton email you receive is legitimate. If you can find the e-mail address of the sender in that support article then the message was likely a "legitimate" direct marketing e-mail trying to push you into purchasing additional Norton LifeLock identity theft protection.
The support article Opt-out of Norton marketing email has instructions on how to change the e-mail preferences in your Norton Account and unsubscribe from these direct marketing e-mails. It didn't help me (I continue to receive these annoying e-mails from norton @ secure.norton.com after disabling Email me product updates, offers, and security newsletters in my Norton Account and clicking the Unsubscribe link at the bottom of these e-mails) but it might work for you.
Please note that there is a separate setting at Settings | Administrative Settings | Special Offer Notification that you can also disable to turn off Norton pop-up ads but this will only turn off ads that pop up on your Windows desktop from the Norton icon in your system tray and won't stop the direct marketing e-mails.
32-bit Vista Home Premium SP2 * Firefox ESR v52.9.0 * Norton Security Premium v18.104.22.168