ldm-inbox-check-mcp is an MCP (Model Context Protocol) server for email deliverability testing, developed by Live Direct Marketing and licensed under MIT. It wraps the Inbox Check service into 5 tools that AI agents can call directly, supporting Claude Desktop, Cursor, Windsurf, Cline, and other MCP-compatible AI clients.
In terms of use, this tool mainly helps users verify where emails land and their authentication status across different email service providers before or after actually sending emails. It is suitable for scenarios such as quality checks for cold email warm-up, debugging authentication issues, comparing template changes, monitoring shared IP reputation, and auditing transactional emails.
Main capabilities include: coverage of 9 real provider mailboxes (Gmail, Outlook, Yahoo, iCloud, AOL, GMX, T-Online, Mail.ru, Yandex), not simulations, but real seed accounts based on IMAP and real filtering determinations; each delivery reports SPF, DKIM, and DMARC alignment, parsed from the Authentication-Results email header; it can detect inbox, spam, promotions, updates, social, forums, and provider-supplied category tabs; it can render screenshots of inbox/spam list views for Gmail, Outlook, etc., letting the agent show users what recipients actually see; the service runs its own seed mailboxes, with no fragile scraping needed, and the agent only communicates with a stable REST API; it provides strict JSON schema via Zod, deterministic tool names, cursor pagination, and idempotency keys, designed specifically for AI agents.
In terms of usage, no global installation is required; Claude Desktop, Cursor, Windsurf, and Cline will run it on demand via npx. Users need to go to https://check.live-direct-marketing.online/docs to obtain an API key (currently it must be obtained by contacting the operator; self-service issuance will be launched later), and the key string will be shown only once. Then add the server configuration in the MCP client configuration file, for example, edit ~/Library/Application Support/Claude/claude_desktop_config.json on macOS or %APPDATA%\Claude\claude_desktop_config.json on Windows; Cursor uses ~/.cursor/mcp.json; Windsurf uses ~/.codeium/windsurf/mcp_config.json; Cline (VS Code) uses the corresponding cline_mcp_settings.json file. Environment variables can override the base URL, but this is only recommended for self-hosted deployments or testing.
Typical prompt examples include: use inbox-check to create tests for Gmail, Outlook, and Yahoo, wait 90 seconds, and then report where the emails landed; list the most recent 10 tests and summarize the spam rate for each provider; create a test, send an email, then display the SPF/DKIM/DMARC results and point out which record is not aligned.
In terms of limitations, the official materials do not provide detailed pricing, rate limits, or specific quota information, and none is currently available; a valid API key is required (currently it must be obtained by contacting the operator); only MCP-compatible clients are supported; accurate results depend on the actual reception situation of the seed mailboxes.
