However, there is interest in developing a mailing list relay system on nostr. A key element for this system would involve the implementation of 'To:' and 'Cc:' tags within notes, allowing the relay to filter and accept only those messages intended for the mailing list. Users would subscribe to these lists by connecting with the relay service and downloading the relevant notes, with their clients caching the information and updating with new notes as they arrive. This process necessitates the addition of specific metadata in each note, signaling its intended destination, such as a particular mailing list. This metadata would be set during the composition of the note, differing from the existing social networking model where the objective is to distribute content widely.

Nostr already accommodates subject lines, akin to email, as some email-like clients demonstrate; an example being the More Speech client available on GitHub. These subjects are treated like any other tag associated with metadata. The preference for emails due to the robust infrastructure they provide is acknowledged, despite the challenges in their management. Notably, from personal experience, running nostr relays is described as being more agreeable than managing email servers.

On the security front, nostr offers an advantage with cryptographic identities and Schnorr signature authentication for its notes. To address potential issues such as spam, it's proposed that an entrance fee could be leveraged via a lightning network payment—a concept warranting further investigation. The sender expresses a commitment to delve deeper into these developments, indicating a future where nostr could evolve into a viable communication platform while retaining its distinct features.