That ship has sailed, but you have to sign up with a mail account that offers throw away addresses (like yahoo! mail or others). They just put the mails from all throwaways also into you main mailbox. If later you can’t ubsubscribe, you can just delete the throwaway. Only problem is, for replies you have to use the mail providers way (i.e. webmailer) so your client doesn’t reply with your main address. But I found it very rare I reply to mails from subscriptions.