InboxPolicy vs Truelist

By Aria Pramesi, founder of InboxPolicy · Updated July 9, 2026

Truelist advertises flat-rate, unlimited email validation: no credits, no per-email charges, starting at $39/mo for low-throughput checking up to $199/mo for its fastest tier, as of July 2026. InboxPolicy is priced the opposite way: $0.01 per verification, pay-per-call via x402 with no account, or prepaid packs from $3.16-$5.00/1k, returning a send/hold/avoid decision with SMTP evidence rather than a status field. Which is cheaper depends on your monthly volume; neither tool can fully resolve catch-all addresses with certainty, whatever either vendor's marketing implies.

What does each tool return: a validation status or a send decision?

Truelist runs SMTP verification, MX/DNS checks, spam-trap detection, disposable-address identification, and what it calls "Enhanced Validation" — heuristics and third-party data cross-referencing the company says deliver "up to 2x more accurate results than other providers." That's a marketing claim we have not independently verified; Truelist publishes no specific accuracy percentage we could find. The output is a result code: valid, invalid, catch-all, disposable, role-based, or unknown, plus a confidence score.

InboxPolicy checks syntax, MX, and live SMTP against its own verification engine, then a deliverability policy turns that evidence into one of five actions: send, send_with_caution, review, retry_later, or avoid, along with a confidence score and the SMTP evidence behind the call. Truelist hands back a status your code has to interpret; InboxPolicy hands back the interpretation.

How does Truelist handle catch-all and accept-all addresses?

Background: our catch-all email verifier guide covers why these addresses cannot be confirmed by SMTP alone.

Truelist's marketing pages state that, unlike competitors that label catch-all domains "unknown," its layered validation approach resolves these addresses to valid or invalid through multiple verification strategies and third-party data cross-referencing. That's an attributed vendor claim we could not independently verify. Notably, Truelist's own developer documentation elsewhere lists catch-all and unknown as distinct result codes in its API responses, which suggests some uncertainty survives the "layered validation" pass rather than being fully eliminated.

InboxPolicy takes the structural position that no verifier, including InboxPolicy's own, can confirm a catch-all mailbox exists through SMTP alone. Unknown or catch-all results always map to the action review, or send_with_caution under an aggressive policy setting, never guessed safe. Roughly 30-40% of B2B addresses sit on catch-all domains, so this is not an edge case.

How do InboxPolicy and Truelist prices compare?

As of July 2026, Truelist's published plans are flat monthly subscriptions with unlimited validations and unlimited lists (each capped at 250,000 emails): Basic $39/mo (up to 1 email/sec, no API access), Growth $69/mo (up to 3 emails/sec, API access included), Pro $129/mo (up to 10 emails/sec), and Elite $199/mo (up to 25 emails/sec, SOC 2 Type II compliance available). Higher-throughput custom plans (50+ requests/sec, white labeling, SSO) are available on request. "Enhanced Validation" is included, though Truelist also sells separate enhanced-validation credits for deeper checks on top of the flat fee, which is worth noting since it complicates the "no credits" pitch. New accounts get 200 free validations plus 10 enhanced credits, no card required; Truelist's homepage separately advertises unlimited free single-email lookups through its web-based checker, a claim we could not fully reconcile with the 200-credit account allowance.

InboxPolicy charges $0.01 per fresh verification pay-per-call via x402 (equivalent to $10/1k), with no account or API key required, or prepaid credit packs: Starter $5 for 1,000 credits ($5.00/1k), Builder $19 for 5,000 ($3.80/1k), Growth $79 for 25,000 ($3.16/1k). There is no free tier, deliberately: free tiers attract list-cleaning abuse. Cache re-verification within 72 hours (from_cache), malformed-email rejection before SMTP, and idempotent retries on the same key are always free.

The two pricing models solve different problems. Truelist's flat fee rewards steady, high monthly volume: run 500,000 verifications a month on the Elite plan and the effective cost is a fraction of a cent per email, undercutting InboxPolicy's per-call and prepaid pricing at that scale. Run a few hundred a month, or verify sporadically from an agent with no predictable schedule, and a $39-69/mo commitment can cost more per email than InboxPolicy's $0.01 x402 call or its prepaid packs.

Can AI agents use Truelist through MCP or x402?

We found no MCP server and no x402 payment support anywhere on Truelist's site or documentation as of July 2026. Its REST API (endpoints including POST /api/v1/verify and a faster verify_inline path, both bearer-token authenticated) is gated behind the Growth plan ($69/mo) or higher, requires an account, and supports batch jobs with webhook callbacks. Response times on the inline endpoint are reportedly 80-200ms for simple checks.

InboxPolicy is built agent-first: it ships an MCP server exposing decide_send, verify_email, batch, and usage tools, purpose-built for agents deciding whether to send rather than parsing a status field. Its keyless x402 flow is, in this comparison, unique — an agent with no account sends a request, receives an HTTP 402 with machine-readable payment requirements, pays $0.01 USDC on Base via a PAYMENT-SIGNATURE header, and gets back a decision plus an on-chain settlement receipt in the same call. The REST API also supports idempotency keys, per-item batch results, async batches up to 50,000 emails (5,000 via keyless x402), and signed completion webhooks.

When does Truelist win?

Truelist is a reasonable fit if:

• You run consistent, high-volume list validation every month and want a predictable flat bill instead of a per-email credit balance that ticks down.
• You want built-in integrations with Mailchimp, Klaviyo, HubSpot, Zapier, Make, Clay, or ConvertKit without custom API work.
• You want recurring, scheduled re-verification of the same list without watching a credit balance, since Truelist's pitch is that re-checks don't cost extra under a flat plan.
• You need SOC 2 Type II compliance documentation, available on Truelist's Elite tier.

When does InboxPolicy win?

InboxPolicy is built for agents and applications deciding whether to send a specific email right now, not for a recurring list-cleaning subscription. Specific fits:

• You verify sporadically or unpredictably and don't want a monthly commitment: pay $0.01 per call, only when you call.
• You're building an agent that needs to reason about whether to send, not parse a status field: the API returns an explicit action with confidence and SMTP evidence.
• You want to skip account creation entirely: the keyless x402 flow needs no signup, no API key, and no monthly plan tier to unlock API access.
• You need an MCP server for LLM tool-calling out of the box, with decide_send, verify_email, batch, and usage tools.

Related comparisons and resources

See the full comparison hub for every InboxPolicy matchup, including InboxPolicy vs Clearout and InboxPolicy vs ZeroBounce. For a broader view of how send-decision APIs stack up against status-field verifiers generally, see Best Email Verification API (2026). Full credit-pack breakdowns live on the pricing page, and the complete REST/MCP reference is in the API docs.

Frequently asked questions