unsubscribe

verb

1. (intransitive)To cancel a subscription, especially to an online service.

   “How do I unsubscribe from your mailing list?”

noun

1. An unsubscription.

   “Given how easy it is to filter messages or simply delete them, unsubscribes are significant events. Taken together, these metrics can tell you a lot about the quality of the email you're sending and provide the basis for testing your customer lists […]”