MailCheck API (Unclaimed)
Email address and domain checks for AI agents: syntax, MX, disposable/role/free flags, typo suggestions, SPF/DMARC/DKIM, RDAP and a deliverability grade. Pay per item with x402 (USDC on Base) or Lightning sats. No signup. Client note: Send a descriptive User-Agent header (e.g. User-Agent: mailcheck-client/1.0). Cloudflare blocks Python urllib's default User-Agent ("Python-urllib/3.x") on workers.dev with HTTP 403 "error code: 1010" before the request reaches this API. curl, python-requests and fetch work as-is. No API key is needed. Data: x402-list.com (CC BY 4.0) Credit: 402 Index (MIT)
Listed · $0.001 USDC/request · 1 endpoint · Tools · base network · x402 protocol
Networks: Base (accepted)
Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.
url https://payapi.market/mcpListing facts
- Provider
- Unclaimed
- Hosted at
mailcheck.toolschemaforge.workers.dev- Category
- Tools
- Price
- $0.001 USDC per request
- Endpoints
- 1
- Payment networks
- Base
- Settlement-verified
- Not yet. Listed, not paid for by PayAPI Market.
- Listed on PayAPI Market
- 2026-10-30
About this API
MailCheck API is listed in the Tools category with pricing at $0.001 USDC/request.
Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.
This API exposes 1 endpoint.
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Paste this on your site. The link points at this listing. Listing is free and providers keep 100%.
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Questions about this API
What does MailCheck API do?
Email address and domain checks for AI agents: syntax, MX, disposable/role/free flags, typo suggestions, SPF/DMARC/DKIM, RDAP and a deliverability grade. Pay per item with x402 (USDC on Base) or Lightning sats. No signup. Client note: Send a descriptive User-Agent header (e.g. User-Agent: mailcheck-client/1.0). Cloudflare blocks Python urllib's default User-Agent ("Python-urllib/3.x") on workers.dev with HTTP 403 "error code: 1010" before the request reaches this API. curl, python-requests and fetch work as-is. No API key is needed. Data: x402-list.com (CC BY 4.0) Credit: 402 Index (MIT) It is provided by Unclaimed.
How much does MailCheck API cost?
MailCheck API is priced at $0.001 USDC per request, paid per call with no subscription. The exact amount for each call is in the HTTP 402 response before any money moves.
Do I need an API key or account to use MailCheck API?
No. MailCheck API uses the x402 protocol, so an agent pays per request in USDC on Base and gets the response, with no API key, account or signup.
Has MailCheck API been verified?
Not yet. MailCheck API is listed and answers an x402 payment challenge, but PayAPI Market has not paid for a call to it, so it carries no settlement-verified badge.
How does an AI agent find MailCheck API?
Through the free PayAPI Market MCP server at https://payapi.market/mcp, using search_apis or get_api, or over plain HTTP at https://payapi.market/agent/search. Discovery is free; the agent pays the provider directly on the listing's own 402.
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