🦦 MailFerret

Verified work emails for AI agents and the people running them.

Give it a name and a company domain. MailFerret tries the usual corporate patterns against the company's live mail server (SMTP RCPT, no email is ever sent), detects catch-all domains, and returns the mailbox the server actually confirms.

Endpoint	Price (USDC)	Charged when
`POST /find` {first_name, last_name, domain}	$0.01	only when a mailbox is verified
`POST /domain` {domain}	$0.005	always (mail provider, catch-all, SaaS tools from SPF, DMARC, public emails, pattern)
`POST /company` {domain}	$0.008	always (name, description, logo, socials, website tech, email setup)
`POST /verify` {email}	$0.003	a definitive answer (deliverable / undeliverable / catch-all)

Paid with x402 on Base or Arbitrum. No signup, no API key, no subscription. Not found, catch-all guesses and inconclusive checks return 4xx/5xx and cost nothing.

📊 New data: 56% of YC startup domains are catch-all (499 companies checked).

Try it free (5/day)

Takes 2-10 seconds.

From an agent

With AgentCash (works in Claude Code, Codex, Cursor):

npx agentcash fetch https://mailferret.appin60.com/find -m POST \
  -b '{"first_name":"Peer","last_name":"Richelsen","domain":"cal.com"}'

Any x402 client works: @x402/fetch, x402-axios, Coinbase AgentKit. Machine-readable: /openapi.json · /llms.txt · /.well-known/x402 · public payment log: /stats

Cleaning a whole list? (for people, no wallet setup)

Send us a CSV of emails and we return it with a status per row: deliverable, undeliverable, catch-all, no MX, role, disposable. $4 per 1,000 addresses (minimum $2), paid in USDC on Base or Arbitrum after you see the quote. Delivered within a few hours.

MCP (Claude Desktop, Claude Code, Cursor)

Remote MCP server, free for 10 calls a day: https://mailferret.appin60.com/mcp. Claude Code: claude mcp add --transport http mailferret https://mailferret.appin60.com/mcp. Tools: find_work_email, verify_email, domain_email_intel.

What it can't do

Catch-all domains accept every address, so no SMTP checker can confirm a mailbox there. MailFerret tells you the domain is catch-all, gives the most likely pattern for free, and doesn't charge.
Some mail servers (Proofpoint, Mimecast, strict greylisting) refuse verification. You get a 503 and aren't charged.
It finds addresses from names you supply. It does not look up who works where.

Use it for legitimate B2B outreach and list hygiene, and follow anti-spam law (CAN-SPAM, GDPR) when you email anyone. Contact: [email protected]