GPTmail

Every inbox. One private workspace.

An open-source workspace for your compatible mail accounts, with a password-protected dashboard and an OAuth-protected MCP connection for ChatGPT. Deploy your own instance, connect your inboxes, and decide what your AI assistant can do.

GPTmail brings multiple accounts into one browser workspace. Search and read a selected mailbox, then selectively enable sending, replying, forwarding, flagging, moving and trashing messages. Each MCP capability is controlled from the dashboard. Outgoing mail and Trash actions can require a second approval in the dashboard; both approval switches are ON by default.

• Free-tier-friendly: FastAPI on Vercel + a persistent Upstash Redis database (check each service's current terms and quotas).

• Multiple providers: Standard IMAP/SMTP accounts, plus Gmail and Microsoft OAuth after you configure your own provider app registrations.

• Encrypted credentials: IMAP/SMTP account records and pending outbound drafts encrypted with Fernet before storage.

• Remote MCP: Streamable HTTP at /mcp, compatible with MCP 2025 and the 2026-07-28 stateless revision.

• OAuth: Authorization Code + PKCE (S256), Dynamic Client Registration, scoped owner consent, bearer tokens and rotating refresh tokens.

• Single-owner: A password-protected private admin dashboard. Your public source code does not make your deployed mailbox public.

• MIT licensed. Python, HTML, CSS and vanilla JavaScript; no OpenAI API key required.

Private by design, with a clear data boundary: Mail credentials and provider tokens stay in encrypted server-side storage. Email content you ask ChatGPT to read is sent to ChatGPT. Email content is untrusted third-party data, not instructions. Sending is initially disabled. GPTmail is an early single-owner project; it has not undergone an independent security audit.

Türkçe kurulum · Mail provider setup · Security · Contributing

Brand assets: transparent logo · launch card · promotion notes.

Find GPTmail useful? Star the repository to help others discover it. Setup feedback, bug reports and contributions are welcome. Please keep mailbox content, account details and secrets out of public issues.

Which inboxes can I connect?

You can add several accounts, including several accounts from the same provider. An account must pass an IMAP connection check before it is saved. SMTP is optional; a readable mailbox does not automatically have permission to send.

Provider OAuth setup is required. Google/Microsoft buttons become available only after the deployment has its own client ID and secret. The public repository does not include a shared OAuth app, credentials or connected mail accounts. “Every inbox” expresses the workspace goal; compatibility depends on the provider and account policy. See the setup guide and limitations.

Related MCP server: mcp-mail

Available MCP tools

Approval switches are separate: send_approval = true and delete_approval = true by default. Turning those switches off allows enabled tools to execute directly, subject to ChatGPT's own confirmation/permission settings. The dashboard owner can also manage their own mail manually, independently of the MCP policy.

1. Prerequisites

• A GitHub account and a Vercel account with access to an appropriate deployment plan.

• An Upstash Redis database with its REST URL and read/write REST token. The Vercel marketplace integration can set these environment variables for you.

• Python 3.11+ to generate secrets, or a local Python setup.

• An IMAP mailbox with SSL/TLS access, and SMTP access if you want outbound mail. Use a provider-supported app password, or configure Google/Microsoft OAuth for accounts that require it.

2. Create the public GitHub repository

Create an empty public repository named GPTmail in your GitHub account. Add the contents of this project; do not commit .env. For the authenticated ozandikici account, the included publishing helper can do this in one step if GitHub CLI (gh) and Git are installed:

# Windows PowerShell, from the GPTmail folder
./scripts/publish_github.ps1

# Linux / macOS, from the GPTmail folder
bash scripts/publish_github.sh

First run gh auth login. The script creates ozandikici/GPTmail as a public repo; if you are publishing under a different username, change the target owner in the script. Alternatively, create the repository manually and run:

cd GPTmail
git init
git branch -M main
git add .
git commit -m "feat: initial GPTmail open-source release"
git remote add origin https://github.com/ozandikici/GPTmail.git
git push -u origin main

If GitHub creates an initial README on its own, reconcile that commit before pushing (or create an empty repo).

3. Configure Upstash + Vercel

1. Import the GitHub repository into Vercel. Vercel recognizes the root-level app.py FastAPI application without a vercel.json file.

2. Create a free-tier-compatible Upstash Redis database and connect it to the Vercel project, or set the REST credentials yourself.

3. Generate a strong password hash and encryption key locally:

   python -m pip install -r requirements.txt
   python scripts/make_secrets.py

4. Set the following Vercel project Environment Variables (Production environment):

   Variable	Example / meaning
   APP_BASE_URL	https://your-project.vercel.app (exact production URL, no trailing slash)
   ADMIN_PASSWORD_HASH	Output from scripts/make_secrets.py
   DATA_ENCRYPTION_KEY	Output from scripts/make_secrets.py
   UPSTASH_REDIS_REST_URL	Upstash REST HTTPS endpoint
   UPSTASH_REDIS_REST_TOKEN	Upstash read/write REST token

5. Deploy/redeploy after setting the variables. If the production URL is not known until the first deployment, set/update APP_BASE_URL after that deployment and redeploy.

6. Open the deployed app and log in using the original password you chose when generating ADMIN_PASSWORD_HASH.

7. Add your account under Accounts. Choose Google/Microsoft OAuth after completing provider setup, or enter your provider's IMAP/SMTP settings. The server verifies the connection before saving encrypted credentials. Add each mailbox separately.

For Gmail or Microsoft sign-in, also configure the optional provider variables documented in Mail provider setup: GOOGLE_CLIENT_ID, GOOGLE_CLIENT_SECRET, MICROSOFT_CLIENT_ID, MICROSOFT_CLIENT_SECRET, and optionally MICROSOFT_TENANT_ID. Keep all secrets in deployment settings or your ignored local .env file.

Keep DATA_ENCRYPTION_KEY unchanged across redeployments: changing it makes existing encrypted account entries and pending requests unreadable. You can intentionally rotate it after first removing/re-adding all mail accounts.

4. Connect ChatGPT

The MCP endpoint is:

https://your-project.vercel.app/mcp

In a ChatGPT workspace that supports custom/private remote MCP plugins, add a custom connection with this HTTPS server URL and choose OAuth authorization. ChatGPT discovers /.well-known/oauth-authorization-server and /.well-known/oauth-protected-resource metadata, registers a public OAuth client (DCR), and redirects to GPTmail for one-owner authorization. Enter your GPTmail admin password and consent to the connection. The password is not shared with ChatGPT.

Once linked, use prompts such as:

• “List the accounts available in GPTmail, then summarize my 10 newest emails.”

• “Search my company mailbox for the latest inspection documents.”

• “Prepare a reply to this email and ask me before sending it.”

Enable Reply or Send in the GPTmail permissions tab before attempting write actions. When Send approval is on, the MCP tool queues an outgoing message and the dashboard owner must explicitly approve it. The model cannot silently bypass the server-side check. After modifying permissions, the ChatGPT tool list may need to be refreshed or the connection reloaded.

Custom MCP/plugin availability depends on ChatGPT account/workspace permissions; deployment alone does not install the plugin into your ChatGPT account. This repository is an MCP server, not a published ChatGPT Plugin Directory listing.

Run locally

python -m venv .venv
# On Windows: .venv\Scripts\activate
# On macOS/Linux: source .venv/bin/activate
pip install -r requirements.txt
# Copy .env.example to .env and edit it with real values
uvicorn app:app --host 127.0.0.1 --port 8000 --reload

Visit http://localhost:8000. Local mode still requires an Upstash database for persistence. localhost is not reachable from ChatGPT's cloud connection: deploy to HTTPS for remote MCP use.

Security model and known limitations

• Secrets: No credentials, token values, message content, subject lines or recipients are stored in the audit log. Raw mailbox credentials are encrypted with a server-owned encryption key and never returned in dashboard state or MCP tool responses.

• Authentication: No anonymous MCP tools. OAuth access tokens live 1 hour; refresh tokens live 30 days and are one-time/rotating. Revoke all connected clients from the dashboard to invalidate all older access and refresh tokens.

• Authorization: The server checks the current permission again on every tool call; cached client-side tool lists do not override current policy. Queued actions must also pass permission checks at approval time.

• Safer deletion: Delete means move to Trash, not permanent removal. Moving requires IMAP MOVE support; insecure EXPUNGE fallbacks are deliberately avoided.

• Message limits: Individual messages over 14 MB are not read; retrieved attachment payloads are capped at 2 MB; displayed body text at 25,000 characters; outbound plain-text bodies at 80,000 characters; max 20 recipients. Forwarding only includes original text, not original attachments.

• Provider access: Google/Microsoft OAuth requires the deployment owner's app registration. Consent, test-user restrictions, tenant rules, IMAP availability and SMTP AUTH settings can block access. No provider policy is bypassed, and universal mailbox compatibility is not claimed.

• OAuth: DCR + S256 PKCE, no CIMD advertisement. Owner password entered only into the self-hosted authorization page. Custom OAuth is intentionally minimal and should undergo external security review before public multi-user SaaS deployment.

• Rate limits: OAuth endpoints and outgoing mail operations are rate-limited. Serverless database access and mail calls rely on external network availability.

• Costs: GitHub's public repository hosting can be free; Vercel Hobby has usage/acceptable-use limits; Upstash has a free tier with quotas. Review their current plan terms before commercial or high-volume use.

• Testing: Automated tests cover owner sessions, OAuth/PKCE, protocol responses, permission defaults and input validation. The maintainer's deployment has completed a real ChatGPT OAuth connection and unauthenticated endpoint checks. Live provider mailboxes have not yet been used for an end-to-end IMAP/SMTP or Gmail/Microsoft OAuth test. A passing test suite is not a security audit.

The maintainer's deployed instance is a private, password-protected workspace, not a public demo or shared mail service. Use this repository to deploy your own instance.

Development

pip install -r requirements.txt pytest httpx
pytest -q

PRs and security improvements are welcome. See SECURITY.md and CONTRIBUTING.md.

License

MIT © 2026 GPTmail contributors.