Invasion of Spam Mail from Shady Real Estate Investor

Want to inquire from the Brownstoner hive mind: are you overwhelmed with spam inquiries from real estate investors trying to buy your property all cash for low prices? I am very annoyed as I am unable to unsubscribed from these pesty mails. One of them in particular, Dolphin Properties, just keeps sending them and when I ask them to unsubsribe me they hang up the phone. How do you deal with that? All I do is getting drowned in junk mail… Thank you.