yahoo-mail-mcp

Safely audit and clean up large Yahoo Mail backlogs from any MCP client. yahoo-mail-mcp scans header metadata, groups mail by account and sender domain, and keeps review separate from mailbox mutation.

Message bodies and attachments are never downloaded or indexed.

What it does

• Scans very large Yahoo mailboxes without downloading message bodies.

• Resumes interrupted historical scans and incrementally picks up new mail.

• Browses and searches cached sender, subject, date, size, and unsubscribe data.

• Lists one-click, mailto, and manual unsubscribe candidates without exposing URLs.

• Groups activity by account and exact sender domain.

• Supports Keep, Needs Review, Archive, Delete, and Unsubscribe decisions.

• Moves deleted mail to Trash without permanent expunge.

• Runs locally over stdio or remotely over authenticated Streamable HTTP.

• Supports one account with simple variables or multiple explicitly scoped accounts.

Related MCP server: Gmail MCP Server

How cleanup works

1. Connect with a Yahoo app password.

2. Scan message headers into SQLite.

3. Review messages or sender groups.

4. Tag an account/domain pair with a decision.

5. Preview the exact affected snapshot.

6. Approve execute_decisions to Archive, move to Trash, or unsubscribe.

Nothing modifies Yahoo Mail until execute_decisions runs against an explicitly tagged account and sender domain.

Five-minute local setup

Requirements:

• Python 3.11 or newer

• uv

• A Yahoo app password

• An MCP client such as Cursor or Claude Desktop

Generate an app password from Yahoo Account Security. Never use your regular Yahoo password.

git clone https://github.com/ktrann24/yahoo-mail-mcp.git
cd yahoo-mail-mcp
uv sync
cp .env.example .env
chmod 600 .env

Edit .env:

YAHOO_ACCOUNT_NAME=personal
YAHOO_EMAIL=you@yahoo.com
YAHOO_APP_PASSWORD=your-yahoo-app-password

Register it with Cursor:

cp .cursor/mcp.json.example .cursor/mcp.json

Replace the placeholder in .cursor/mcp.json with the absolute path to your clone, then restart Cursor. The real file is ignored because it is machine-specific.

Start by asking:

List my configured accounts, then scan up to 100 messages from the Inbox of account personal. Do not modify any mail.

Connect a Notion Custom Agent

Notion needs a publicly reachable Streamable HTTP endpoint. The supported deployment uses Railway with a persistent volume, HTTPS, Host validation, and bearer authentication.

Follow the complete Railway and Notion setup guide.

After connecting, keep Notion's write-tool policy set to Always ask for:

• set_decisions, which only records account-scoped review choices.

• execute_decisions, which performs Archive, Delete, or Unsubscribe actions.

Multiple accounts

Use YAHOO_ACCOUNTS instead of the three single-account variables:

YAHOO_ACCOUNTS='[
  {"name":"personal","email":"one@yahoo.com","app_password":"app-password-one"},
  {"name":"work","email":"two@yahoo.com","app_password":"app-password-two"}
]'

Names must be unique. Sender groups, decisions, previews, and execution are scoped by account. Mutating tools require an explicit account when more than one is configured.

Example MCP prompts

Read-only exploration:

List configured accounts and show the scan status. Do not modify mail.

Start a background scan of at most 100 Inbox messages for account personal, then report the job ID.

Show the largest sender groups for account personal, including counts, recent dates, and available unsubscribe methods.

Show one-click unsubscribe candidates for account personal, sorted by message count. Do not unsubscribe yet.

Safe review:

Tag newsletter.example.com as Archive for account personal. Do not execute the decision.

Preview Archive decisions for account personal and show the exact count and sender breakdown. Do not execute.

Tools

Read and scan:

• list_accounts

• scan_mailbox, start_scan_job, get_scan_job, list_scan_jobs

• get_scan_status, triage_new_mail

• list_recent_messages, search_messages, get_message_headers

• list_sender_groups, get_sender_detail

• list_unsubscribe_candidates

Review and mutation:

• set_decisions: records an account/domain decision without touching mail.

• preview_cleanup: returns exact counts and a short-lived confirmation token.

• execute_decisions: performs approved Archive, Delete, or Unsubscribe actions.

• export_review_csv, import_review_csv: local-only spreadsheet round trip.

Remote mode intentionally omits CSV tools because arbitrary server filesystem paths are unsafe over the network.

Safety and privacy

• Scans use read-only folders and BODY.PEEK for selected header fields.

• UIDVALIDITY changes invalidate stale folder data.

• Decisions and mutations are scoped to an explicit account and domain.

• Archive and Delete use recoverable UID MOVE operations.

• Large moves require a 15-minute, single-use token bound to the exact snapshot.

• Live UIDVALIDITY and sender domains are checked before moves.

• One-click unsubscribe blocks private addresses, unrelated domains, DNS rebinding, and redirects.

• Candidate listings identify advertised methods; execution repeats final endpoint and DNS safety validation.

• Destructive actions are written to the SQLite audit log.

• Browse tools do not expose raw unsubscribe URLs.

SQLite stores account aliases, folders, UIDs, sender metadata, subjects, dates, sizes, unsubscribe headers, decisions, checkpoints, and audit logs. It does not store message bodies or attachments. Protect the database and hosting environment as sensitive personal data.

See SECURITY.md for the complete deployment assumptions and private vulnerability reporting process.

Configuration

Common variables:

• YAHOO_EMAIL, YAHOO_APP_PASSWORD, YAHOO_ACCOUNT_NAME: one account.

• YAHOO_ACCOUNTS: JSON array for multiple accounts.

• YAHOO_MAIL_MCP_DB: SQLite path.

• YAHOO_MAIL_MCP_DELETE_THRESHOLD: large-move confirmation threshold.

• YAHOO_MAIL_MCP_BATCH_SIZE: IMAP fetch batch size.

• YAHOO_MAIL_MCP_LOG_LEVEL: Python log level.

Hosted mode also requires a bearer token and allowed hostname. See .env.example and docs/railway.md.

Why Yahoo needs special handling

Large Yahoo mailboxes may expose only a limited standard IMAP window. This project handles Yahoo's UIDONLY, PARTIAL, and MESSAGELIMIT extensions internally, using checkpointed batches and constant memory instead of requiring thousands of MCP tool calls.

Alpha limitations

• This is self-hosted software for one trusted owner, not a multi-tenant service.

• Yahoo app passwords and indexed metadata live wherever it is deployed.

• Very large historical scans may require multiple background jobs.

• Sender-provided unsubscribe headers can be missing or require manual action.

• Live mailbox mutations remain manual release checks.

See the public release checklist.

Development

Use synthetic fixtures only—never commit real mailbox data or credentials.

uv sync
uv run ruff format --check .
uv run ruff check .
uv run mypy src/yahoo_mail_mcp
uv run pytest -q
uv build
uv run twine check dist/*

See CONTRIBUTING.md and CHANGELOG.md.

License

MIT. See LICENSE.