Give your AI access to your email inbox via MCP.

unthinkmail connects to your existing email account over IMAP and exposes it as a remote Model Context Protocol server. Any MCP-compatible AI client can then read, search, and manage your mail as native tools — no copy-pasting, no forwarding, no plugins.

Live at unthinkmail.undivisible.dev

1. Enter your IMAP/SMTP credentials on the hub
2. Get an encrypted API key (um_...) or use OAuth
3. Point your AI client at https://unthinkmail.undivisible.dev/mcp with Authorization: Bearer <your key>
4. Your AI can now search, read, move, and delete mail

The key contains your credentials so the server can connect to your mailbox without storing anything. When OAUTH_SECRET is configured, new keys are encrypted with AES-GCM; legacy base64url um_ keys are still accepted for compatibility.

Outgoing tools that send mail accept to, cc, and bcc as a single address, comma-separated addresses, or an array of addresses. sendemail also accepts recipients for personalized sends: each recipient entry has to, optional cc/bcc, and variables; placeholders like {name} in subject, body, and htmlBody are rendered per recipient. They also accept optional attachments: an array of { filename, mimeType, content }, where content is base64-encoded file content. They also accept contentText, contentBytes, or contentDataUrl so clients can provide raw text, byte arrays, or data URLs and let the server encode them. When files are hosted, prefer sendemailfromurls or attachmentUrls; the server fetches public HTTPS URLs and encodes them before sending. Limits are 25 attachments per email, 10 MB per attachment, and 20 MB total. Use ASCII filenames; non-ASCII names are normalized because outbound MIME filename encoding is not emitted yet. HTML email uses htmlBody; inline images use htmlBody references like cid:logo plus an attachment with contentId: "logo" and inline: true.

Example personalized send:

{
  "subject": "Hi {name}",
  "body": "Hi {name}, your code is {code}.",
  "recipients": [
    {
      "to": "ada@example.com",
      "variables": { "name": "Ada", "code": "A1" }
    },
    {
      "to": "grace@example.com",
      "variables": { "name": "Grace", "code": "G2" }
    }
  ]
}

Example MCP arguments for hosted files:

{
  "to": "person@example.com",
  "subject": "Report",
  "body": "Attached.",
  "attachmentUrls": [
    {
      "url": "https://example.com/report.pdf",
      "filename": "report.pdf",
      "mimeType": "application/pdf"
    }
  ]
}

Example script:

UNTHINKMAIL_KEY="um_..." \
TO="person@example.com" \
ATTACHMENT_URL="https://example.com/report.pdf" \
ATTACHMENT_FILENAME="report.pdf" \
ATTACHMENT_MIME_TYPE="application/pdf" \
bun examples/send-hosted-attachment.mjs

For local files, the hosted Worker cannot read local paths. Use a local script so the file bytes stay out of the chat transcript:

UNTHINKMAIL_KEY="um_..." \
TO="person@example.com" \
ATTACHMENT_FILE="./report.pdf" \
ATTACHMENT_FILENAME="report.pdf" \
ATTACHMENT_MIME_TYPE="application/pdf" \
bun examples/send-local-attachment.mjs

For inline hosted images:

{
  "to": "person@example.com",
  "subject": "Logo",
  "htmlBody": "<p>Inline logo:</p><img src=\"cid:logo\">",
  "attachmentUrls": [
    {
      "url": "https://example.com/logo.png",
      "filename": "logo.png",
      "mimeType": "image/png",
      "contentId": "logo",
      "inline": true
    }
  ]
}

Messages are fetched live from your provider on every request — nothing is cached or stored on our side.

MCP client
  └─ POST /mcp  (Bearer um_...)
       └─ Cloudflare Worker
            ├─ decodes um_ key → credentials
            └─ routes to Durable Object (per credential hash)
                  └─ native TLS IMAP/SMTP via cloudflare:sockets

• Worker (src/index.js) — routing, key decoding, DO dispatch
• Durable Object (src/session.js) — per-connection IMAP/SMTP state, JSON-RPC handler
• IMAP/SMTP (src/imap.js, src/smtp.js) — native TLS via cloudflare:sockets

• Cloudflare account with Workers & Durable Objects
• Wrangler CLI v4+

# 1. Clone
git clone https://github.com/undivisible/unthinkmail
cd unthinkmail

# 2. Set required secrets
wrangler secret put OAUTH_SECRET
# enter any random 32+ character string

# 3. Update wrangler.jsonc with your own route/domain, then deploy
wrangler deploy

bun run dev

• Credentials are carried in the access token so there is no server-side credential storage. Configure OAUTH_SECRET so new tokens are encrypted at rest.
• Each credential set gets its own Durable Object instance
• IMAP/SMTP connections use native TLS via cloudflare:sockets
• Use an app-specific password if your provider supports it (Gmail, Outlook, Fastmail, and iCloud all do). To revoke access, disable the app password at your provider.

Any IMAP/SMTP provider works. Quick-fill presets on the hub: Purelymail, Gmail, Outlook, Fastmail, iCloud.