--- title: "How Subscription Works" slug: "subscription-basics" updated: 2026-08-03T11:05:39Z published: 2026-08-03T11:05:39Z canonical: "docs.mapp.com/subscription-basics" --- > ## Documentation Index > Fetch the complete documentation index at: https://docs.mapp.com/llms.txt > Use this file to discover all available pages before exploring further. # How Subscription Works ## Overview Subscription is how a contact opts in to receive messages, and opt-out is how they stop. In Mapp Engage, subscription is handled at the group level: a contact becomes an active, messageable member of a group by opting in, and leaves that active state by opting out. The contact and their history stay in the system. This page explains how opt-in and opt-out work. For the other ways a contact can be stopped from receiving messages, such as deactivation, blacklists, removal, and anonymization, see [How a Contact Stops Receiving Messages](/v1/docs/engage-how-contacts-stop-receiving-messages). --- ## Opt-in Opt-in records a contact's consent to receive messages in a group. Mapp Engage supports two approaches: - **Single opt-in:** the contact is added to the group and is immediately eligible to receive messages. - **Double opt-in:** the contact receives a confirmation message and must confirm before becoming active. This provides stronger, auditable consent and is recommended wherever proof of opt-in is required. To set up double opt-in, see [Set up Double Opt-in with the Email Channel](/v1/docs/set-up-double-opt-in-with-the-email-channel). To control the pages a contact sees during opt-in, see [Customize the Subscription Link for Opt-In](/v1/docs/customized-landing-pages-for-the-opt-in-processes). --- ## Opt-out Opt-out, also called unsubscribe, removes a contact from the active audience of a group. The contact stays in the system and keeps their history, but no longer receives messages from that group. A contact can opt out of a single group or, through automation, of all groups. Opt-out is reversible: the contact can resubscribe or be added to the group again. --- ## Related - [How a Contact Stops Receiving Messages](/v1/docs/engage-how-contacts-stop-receiving-messages) compares unsubscribe, deactivation, blacklist, removal, and anonymization side by side. - [How Contact Deactivation Works](/v1/docs/deactivation-basics) explains automatic suppression based on deliverability.