Managing subscribers and unsubscribers is crucial in email implementation to respect users' preferences and ensure they receive relevant emails at the right time. Resend Audiences, a new feature, allows for easy management of contacts without worrying about the entire unsubscribe flow. It offers 9 new endpoints to the Resend API, enabling control over audiences and contacts programmatically. Users can add contacts manually or import them via CSV, map fields, and leverage SDKs to add contacts programmatically. Audiences are designed to be used with Broadcasts, allowing for automatic handling of the unsubscribe flow when sending emails. The feature includes proper unsubscribe headers according to Gmail and Yahoo's bulk sending requirements for 2024.