Buyer guide · SimpleVerifier Team
Verify emails inside Claude, Cursor and other AI assistants
SimpleVerifier runs a remote MCP server at https://simpleverifier.com/api/mcp. Add it to ChatGPT or claude.ai by signing in with your SimpleVerifier account, or to Claude Code, Claude Desktop, Cursor, VS Code or Windsurf with an API key, on a Pro, Business or Agency plan. The assistant can then verify one address or up to 100 per call, check a domain's MX, SPF and DMARC, and check phone formats.
The tools are verify_email, verify_emails, get_job_results, check_phone_format, check_domain, get_usage. Each returns valid, risky or invalid with a plain-English reason, the same result the API and the dashboard give. Setup commands for each client are on the MCP docs page.
ChatGPT and claude.ai add a remote MCP server by URL and sign you in with OAuth: you approve a consent screen that lists what the app can do, with no key to copy. Asking ChatGPT itself to "verify" an address without the connector does not check anything: a language model cannot open an SMTP conversation with a mail server, so any verdict it gives without a tool is a guess.
Test it on a real address first
Type any address. It gets the same check the paid plans run: syntax, the domain’s mail servers and, where the provider allows it, a live mailbox check. Nothing is sent to the address.
Five checks a minute, no account needed. Nothing is sent to the address — we ask its mail server whether the mailbox exists, then disconnect.
Have a list? Sign in with Google and the first 100 addresses are checked free, with results to download. No card.
By continuing you agree to our Terms and Privacy Policy.
What it costs
MCP calls are API calls. Pro ($29.99 a month) includes 10,000 calls a month included, then $1.50 per 1,000; Business ($99) includes 100,000 and Agency ($249) 300,000, then $1.00 per 1,000. Starter and Growth do not include API or MCP access. The 100 free checks run in the dashboard, not over MCP.
What the assistant can and cannot tell you
A batch of up to 100 addresses runs as a list job: the call waits up to 45 seconds and returns every result, or a job id the assistant polls with get_job_results. check_phone_format is a numbering-plan check only and never says whether a number is in service. Microsoft consumer mailboxes and iCloud are not probed and come back risky.
Common questions
- Can ChatGPT verify an email address?
- Not by itself. Verifying a mailbox means talking to the recipient's mail server over SMTP, which a language model cannot do without a tool. Add SimpleVerifier's MCP server as a custom MCP server in ChatGPT (steps on the MCP docs page) and sign in with your account on a Pro, Business or Agency plan, or use the free checker on simpleverifier.com.
- How do I add email verification to Claude Code?
- Run: claude mcp add --transport http simpleverifier https://simpleverifier.com/api/mcp --header "Authorization: Bearer YOUR_API_KEY". The key comes from the API keys page on a Pro, Business or Agency plan. In claude.ai, add it under Customize, Connectors, Add custom connector, and sign in instead of using a key.
- How many emails can an AI agent verify per call?
- Up to 100 with verify_emails. Larger lists are better uploaded as a CSV in the dashboard, which does not use API calls.
Get an API key for your assistant
Pro is $29.99 a month and never cuts you off: the first 100,000 emails a month run at full speed, then big lists run slower. CSV uploads, the API (10,000 calls a month, then $1.50 per 1,000), the Google Sheets add-on and the email finder are included, and you can cancel any time. For smaller volumes, Starter is $9 a month for 2,500 emails a month and Growth $19 a month for 10,000 emails a month.
The first 100 email checks are free with a Google sign-in, no card, on the same engine the paid plans use.