Post 🏤

A local mail daemon, MCP server, and CLI — built entirely in Swift.

📖 Read the announcement →

Post pulls together SwiftMail, SwiftMCP, and SwiftText to give you a persistent, local-first email system that keeps tabs on multiple mailboxes across multiple IMAP servers.

Architecture

Post is three things in one package:

postd — The Daemon

A lightweight process that maintains persistent IMAP connections to all your configured mail servers. Optionally, it can use IMAP IDLE on any mailbox (INBOX, Sent, a custom folder, etc.) to get instant push notifications when messages arrive or change. When a change is detected, it can trigger a custom command — a shell script, a webhook call, whatever you need.

MCP Server

The daemon doubles as an MCP (Model Context Protocol) server, exposing your email to AI agents. Agents can list servers, search messages, fetch content, download attachments, move/copy/flag messages, draft emails, and more — all through a standardized tool interface.

post — The CLI

A fast command-line client for searching, reading, downloading, and managing email. Communicates with the running daemon via local Bonjour + HTTP — no separate IMAP connections needed.

post list --server work --limit 10
post fetch 12199 --server work
post fetch 12198,12199 --eml --out ./backup
post search --from "amazon" --since 2025-01-01
post move 12345 Archive
post attachment 12199 --output ./downloads
post attachment 12199 --cid "image-content-id"
post draft --to colleague@example.com --subject "Update" --body email.md

📖 Full CLI User Guide →

How It Works

┌─────────────┐                         ┌──────────────────┐
│  post CLI   │◄── Bonjour + HTTP ─────►│                  │
└─────────────┘                         │                  │──── IMAP IDLE ──► Mail Server 1
                                        │  postd daemon    │──── IMAP IDLE ──► Mail Server 2
┌─────────────┐                         │                  │──── IMAP IDLE ──► Mail Server 3
│  AI Agents  │◄── MCP (TCP) ──────────►│                  │
└─────────────┘                         └──────────────────┘

The daemon holds all IMAP connections. Both the CLI and AI agents talk to the daemon — never directly to mail servers. This means:

• Single connection pool — no duplicate IMAP sessions
• Local-only by default — daemon accepts connections from localhost only (secure by default)
• Instant discovery — CLI finds the daemon via Bonjour on the local machine
• Always up-to-date — IDLE keeps mailbox state fresh
• Trigger scripts — run custom commands when new mail arrives

Key Features

🔐 Secure Credential Storage

Store credentials directly in config (simple) or in a hardware-bound macOS Keychain (recommended). Post creates a private keychain encrypted with your Mac's hardware UUID — credentials never leave your machine.

📝 Markdown Email Drafts

Draft rich HTML emails from plain markdown files. Post handles the conversion and creates drafts in your mail client, ready to review and send.

post draft --to team@company.com \
  --subject "Weekly Update" \
  --body weekly-update.md

🔑 Multi-Agent Access Control

Create scoped API keys that limit which agents can access which mail servers. Perfect for sandboxed agents or multi-tenant scenarios.

post api-key create --servers work     # Work-only token
post api-key create --servers personal # Personal-only token

⚡ IMAP IDLE Push Notifications

Get instant notifications when mail arrives. Perfect for automation workflows like invoice processing, newsletter archival, or notification

... View full README on GitHub