# Messaging Layer If the Identity Layer establishes who you are, the Messaging Layer defines how you communicate. Traditional email is a patchwork: plaintext origins, later bolted-on TLS, clunky MIME attachments, and endless spam countermeasures. It is interoperable, but brittle, surveilled, and inherently insecure. SolMail rethinks messaging as a wallet-native, end-to-end encrypted (E2EE), censorship-resistant protocol that integrates financial primitives, not ads or intermediaries. #### Design Principles 1. Wallet as Inbox: Every Solana wallet can receive messages without requiring extra setup. Users may later opt into a full SolMail mailbox for enhanced UX, but the baseline is universal addressability. 2. E2EE by Default: Encryption is non-optional. Messages are encrypted client-side using ElGamal, attachments with AES-256, and signed with Ed25519. This prevents providers, relayers, or infrastructure nodes from inspecting contents. 3. On-Chain Metadata: Unlike Web2 email headers (easily forged), SolMail enforces cryptographic provenance. Sender, timestamp, and integrity checks are immutably anchored on-chain. 4. Programmability: A message isn’t just text. It may carry tokens, NFTs, invoices, or signed approvals — all verifiable and executable without leaving the inbox
#### Message Format Solmail uses a format inspired by RFC 5322/2045, with a modified structure for decentralized and encrypted messaging. The message layout is divided as follows, where all fields except the version are encrypted, stored in a decentralized network as hashes, and referenced in the Mail’s account buffer. **Header** Header Includes * Version * Encrypted recipient wallet info * Identity proof (handle/domain, tagged as origin) **Body** * Encrypted payload (can be plain text, structured JSON, or command instructions). **Attachments:** * Contains hash mappings for attachments. * Each hash points to a file stored in a chosen decentralized storage provider. **Plugins:** * Each plugin defines its own identifier keys. * Plugin data is structured in JSON and consumed by compatible client-side plugins for rendering. **Audit Trail:** Every message is anchored on the Solana ledger, providing an immutable log while keeping message content private. **Versioning Paradigm:** Unlike semantic versioning, Solmail uses client-based mapping for the major version * 1 = Web client * 2 = Mobile client * 3 = DApp client * Minor and patch versions indicate iterations. #### Inbox = Wallet (Email-as-a-Wallet) The central innovation of SolMail is EaaW (Email-as-a-Wallet). In practice: * A DAO treasurer sends a payroll message → attached token transfers execute with one tap inside the inbox. * A freelancer receives an invoice → the recipient pays instantly via Solana Pay, directly from the message thread. * A DAO circulates a governance proposal → members sign approvals or multi-sig requests within the same thread. The inbox ceases to be a passive communication channel and becomes an active financial and organizational command center. #### Attachments and Storage Attachments are often the weakest link in email security. SolMail addresses this by: * Distributed Storage: Files are uploaded to decentralized storage (e.g., Irys). * Client-Side Encryption: Only recipients hold keys, ensuring no relay or node can leak sensitive files. * Verifiable Integrity: Every attachment is hashed, signed, and logged on-chain, preventing tampering or “man-in-the-middle” substitution. Thus, an attached contract or invoice is as tamper-proof as the blockchain itself. #### Notifications and Real-Time Sync Modern users expect more than just inbox refreshes. SolMail integrates: * Wallet-Native Alerts: Notifications flow directly to Phantom, Solflare, or any Solana wallet. * Push Infrastructure: Mobile apps receive encrypted push notifications without exposing message content. * Battery-Aware Sync: Background updates minimize device resource usage — essential for Solana Mobile and future Seeker integrations. \\