Guides · calculators · benchmark data

Email verification resources for agents that need a decision.

Start here when you need more than a raw valid/invalid status: how to branch on send, review, and avoid; how catch-all evidence works; what x402 changes for agents; and how InboxPolicy pricing compares.

Updated 2026-07-09 · machine-readable summary in llms.txt

Build with the API

REST, MCP, x402, idempotency, batches, and response shapes.

Read API docs →
Model the cost

Compare pay-per-call, credit packs, cache hits, and vendor list-cleaning prices.

Open calculator →
Evaluate decisions

See 40 crawlable scenarios that map input evidence to send decisions.

View benchmark →

Core guides

These are answer-ready pages for the questions agents and technical buyers ask before wiring verification into a workflow.

Send-decision API

Send-decision vs email verification API explains why a direct action beats parsing vendor status fields.

Catch-all handling

What to do with catch-all email addresses covers the 30-40% of B2B addresses where SMTP cannot confirm the mailbox.

AI agents

Email verification for AI agents maps verification evidence to autonomous send/hold behavior.

MCP

MCP email verification for agents shows how an LLM calls decide_send, batch tools, and usage tools.

x402

x402 email verification shows the keyless flow: HTTP 402 quote, PAYMENT-SIGNATURE, then the verified decision.

Free re-checks

Free email re-verification explains the 72-hour cache window and why repeat checks cost 0 credits.

Comparison and data assets

Vendor comparison

Comparison hub, alternatives, and head-to-head pages for ZeroBounce, Kickbox, MillionVerifier, and Emailable.

Benchmark

Send-decision benchmark and benchmark.json publish 40 examples with the input pattern, evidence, action, and rationale.

Pricing truth

Pricing and free-plan policy explain why the trial is $0.01 via x402, while cache re-verification and malformed-input rejection stay free for customers.

FAQ

What email verification resources does InboxPolicy publish?

InboxPolicy publishes guides, comparison pages, an email verification cost calculator, a send-decision benchmark, and machine-readable benchmark JSON. The resource library is built for AI agents and technical buyers who need to understand send decisions, catch-all handling, x402 pay-per-call verification, MCP integration, and the economics of re-verification before they wire the API into production.

Which InboxPolicy resource should an AI agent read first?

An AI agent should start with llms.txt for the compact product summary, then read the API docs for the live contract, the send-decision benchmark for example input-to-output behavior, and the x402 guide if it needs keyless pay-per-call access. The comparison pages help when the agent is choosing between InboxPolicy, ZeroBounce, Kickbox, MillionVerifier, or Emailable.

Need a live decision instead of another guide?

Use x402 for one keyless $0.01 call, or buy a credit pack and receive an API key by email.

Start with the API