# Mail Security Tools, pay as you go: Email verification API

> Free DMARC, SPF, DKIM and MX checks for any domain, from mailsecuritytools.com. Paid (x402 USDC on Base): a $0.01 graded email security score, a $0.01 email address check, a $0.50 bulk score of up to 100 domains.

Mail Security Tools's x402 plan for the email verification API costs $10.00 per 1,000 emails. We check each provider's docs for 6 fields. Mail Security Tools's docs list 1: Deliverability.
We haven't run Mail Security Tools through [our email verification API benchmark](https://datacircle.dev/best-email-verification-api.txt) yet.
We rank 4,391 plans for email verification APIs by price. Half the plans cost $2.00 or less per 1,000 emails. This plan costs less per 1,000 emails than 10% of the 4,391 plans.
[treg's top-up from $10](https://datacircle.dev/validate-email-apis/treg/top-up-from-10/llms.txt) is the cheapest paid plan per 1,000 emails: $0.00 on average. treg asks one provider after another until one answers. You pay $68.365 per 1,000 emails when no provider answers. [StableEnrich's pay-as-you-go plan](https://datacircle.dev/validate-email-apis/stableenrich/pay-as-you-go-pay-per-request-with-x402-or-mpp-post-api-minerva-validate-emails/llms.txt) costs the least for 10,000 emails a month: $0.05.
[Disify's $9 monthly plan (/email)](https://datacircle.dev/validate-email-apis/disify/9-monthly-starter-post-email/llms.txt) covers any number of emails. Disify's $9 monthly plan costs less up front than treg's top-up from $10.
[pingutil](https://datacircle.dev/validate-email-apis/pingutil/free-api-key-post-v1-verify/llms.txt), [Validemail.co](https://datacircle.dev/validate-email-apis/validemail-co/9-90-monthly-9-90-month-get-api-v1-validate/llms.txt) and [looot](https://datacircle.dev/validate-email-apis/looot/top-up/llms.txt) are the best email verification API providers in the Datacircle benchmark.

- This page: https://datacircle.dev/validate-email-apis/mail-security-tools/pay-as-you-go
- [Email validation API: best verification providers compared](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://api.mailsecuritytools.com/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Request: `GET https://api.mailsecuritytools.com/v1/email-check`
- API key: not needed
- Its API docs: https://api.mailsecuritytools.com/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- Sold by: Mail Security Tools (https://mailsecuritytools.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing)
- Checked: 2026-11-10

## In the answer

- Completeness: 17%
- Deliverability: ✓

## Price

- $ per 1,000 emails: $10.00
- Per: call
- Billing: pay as you go

## Aggregators

- Aggregators: none

## Charges

- Also pays for: nothing else

## In their words

- Their pitch: Free DMARC, SPF, DKIM and MX checks for any domain, from mailsecuritytools.com. Paid (x402 USDC on Base): a $0.01 graded email security score, a $0.01 email address check, a $0.50 bulk score of up to 100 domains.

## Data

- What it checks: format, mail servers, disposable domains, role addresses
- Keep data: no API terms
- Use data: no API terms

## Plan

- Pay: per call

## Rate limit

- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: email
- Method: GET
- Path: /v1/email-check

## About the plan

- Plan: x402
- Who can get it: anyone

## The 5 fields the plan's answer can hold

syntax valid, MX record found, disposable, role address, verdict

## Mail Security Tools's plans (1)

- [Mail Security Tools, pay as you go](https://datacircle.dev/validate-email-apis/mail-security-tools/pay-as-you-go/llms.txt): $10.00 per 1,000, 17% complete

## Mail Security Tools's calls (1)

- `GET /v1/email-check`: [Mail Security Tools, pay as you go](https://datacircle.dev/validate-email-apis/mail-security-tools/pay-as-you-go/llms.txt)

## Mail Security Tools's APIs (1)

- [Mail Security Tools: email verification API pricing, 1 plan](https://datacircle.dev/validate-email-apis/mail-security-tools/pay-as-you-go/llms.txt)

## Mail Security Tools: email verification API alternatives

- [Tuski, pay as you go](https://datacircle.dev/validate-email-apis/tuski/pay-as-you-go/llms.txt): $10.00 per 1,000, 50% complete
- [Clearout, $1,000 pack, 500,000 credits, POST /email_verify/instant, Instant Verify, full](https://datacircle.dev/validate-email-apis/clearout/1000-pack-500000-credits-post-email-verify-instant-instant-verify-full/llms.txt): $10.00 per 1,000, 50% complete, live
- [InboxPolicy, pay as you go, Pay-per-call (x402), POST /v1/decide](https://datacircle.dev/validate-email-apis/inboxpolicy/pay-as-you-go-pay-per-call-x402-post-v1-decide/llms.txt): $10.00 per 1,000, 50% complete, 72 hours
- [Catch-all Verifier, $25 pack, 2,500 Credits, POST /api/v1/verify/single](https://datacircle.dev/validate-email-apis/catch-all-verifier/25-pack-2500-credits-post-api-v1-verify-single/llms.txt): $10.00 per 1,000, 33% complete, live

## Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-11-10.

- https://api.mailsecuritytools.com/?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://api.mailsecuritytools.com/.well-known/x402?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://api.mailsecuritytools.com/llms.txt?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://api.mailsecuritytools.com/openapi.json?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing
- https://mailsecuritytools.com?utm_source=datacircle.dev&utm_medium=referral&utm_campaign=email-verification-api-pricing