Transport: Multi-Provider Email Transport

The Problem

Email transport adapters for different providers are fragmented. No unified interface exists for sending both regular email and encrypted shares across Gmail, Outlook, and Yahoo.

Each email provider exposes a different API surface. Gmail uses REST with base64url message encoding. Microsoft Graph uses a JSON-based payload format. Yahoo requires IMAP over OAuth. Building reliable transport across all three means maintaining three completely separate codebases with different authentication, error handling, and rate limiting models.

When shares from XorIDA split operations need to be routed through these providers, the problem compounds. Each share must travel through a different provider to achieve channel independence, but the transport layer must handle this routing transparently without the application layer knowing which provider carries which share.

The Old Way

The PRIVATE.ME Solution

A unified TransportAdapter interface abstracts provider differences. One API for regular email, share routing, token refresh, and reconnection across Gmail, Outlook, and Yahoo.

The adapter pattern encapsulates provider-specific logic behind a common interface. Application code calls sendShare() or sendEmail() without knowing which provider handles the request. The transport layer automatically routes shares to the correct provider channel based on the sender's connected accounts.

Deferred delivery handles the case where a recipient is not yet on Xail: Share 1 is delivered as a "message waiting" teaser, Share 2 is held locally in a Pending folder until the recipient joins. When they do, the held share auto-delivers and the sender is notified.

The New Way

How It Works

The transport layer detects available provider channels, routes shares across independent channels for maximum security, handles token refresh transparently, and implements deferred delivery for non-Xail recipients.

Use Cases

Integration

import { createAdapter, sendShare } from '@private.me/transport';

// Create a provider adapter
const gmail = createAdapter('gmail', oauthToken);

// Send regular email
await gmail.sendEmail({
  to: 'recipient@example.com',
  subject: 'Hello',
  body: 'Regular email content',
});

// Route an XorIDA share through this channel
await sendShare(gmail, {
  share: shares[0],
  recipient: 'user@private.me.io',
  uuid: messageUuid,
});

Security Properties

Ship Proofs, Not Source

Transport generates cryptographic proofs of correct execution without exposing proprietary algorithms. Verify integrity using zero-knowledge proofs — no source code required.

Use Cases