# Mails.so, free: Email validation API

> Email Validation API: Clean Lists, Boost Deliverability & Maximize ROI. Remove fake emails and spam users from your email lists.

Mails.so's email validation API on its Free plan, $0.00 per 1,000 emails. 4 of the 6 key fields: Address, Its check, Confidence, Company.

- This page: https://datacircle.dev/validate-email-apis/mails-so/free
- Get it: https://mails.so
- Its API docs: https://docs.mails.so/single
- Sold by: Mails.so (https://mails.so)
- Checked: 2026-10-20

## In the answer

- Completeness: 67%
- Address: ✓
- Its check: ✓
- Confidence: ✓
- Company: ✓

## Price

- $ per 1,000: $0.00
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Per: call
- Also pays for: nothing else

## Not found

- $ per 1,000: $0.00

## In their words

- Their pitch: Email Validation API: Clean Lists, Boost Deliverability & Maximize ROI. Remove fake emails and spam users from your email lists.

## Data

- Keep data: no limit
- Use data: any

## Plan

- Pay: €0
- You get: 50 credits
- Enough for: 50 calls

## Rate limit

- Batch: 1

## Speed

- Answer: in the call

## The call

- You send: email
- Method: GET
- Path: /validate

## About the plan

- Plan: Free
- Who can get it: anyone

## The 16 fields the plan's answer can hold

id, email, username, domain, MX record, score, valid format, valid domain, valid MX record, not blocked, no catch-all, not generic, free email provider, result, reason, error

## Mails.so's plans (4)

- [Mails.so, free](https://datacircle.dev/validate-email-apis/mails-so/free/llms.txt): $0.00 per 1,000, 67% complete
- [Mails.so, €48 monthly, Pro, GET /validate](https://datacircle.dev/validate-email-apis/mails-so/48-monthly-pro-get-validate/llms.txt): $5.401 per 1,000, 67% complete
- [Mails.so, €98 monthly, Business, GET /validate](https://datacircle.dev/validate-email-apis/mails-so/98-monthly-business-get-validate/llms.txt): $2.206 per 1,000, 67% complete
- [Mails.so, €498 monthly, Unlimited, GET /validate](https://datacircle.dev/validate-email-apis/mails-so/498-monthly-unlimited-get-validate/llms.txt): no limit per 1,000, 67% complete

## Mails.so's calls (2)

- `GET /validate`: [Mails.so, free](https://datacircle.dev/validate-email-apis/mails-so/free/llms.txt)
- `POST /batch`: [Mails.so, €48 monthly, Pro, POST /batch](https://datacircle.dev/validate-email-apis/mails-so/48-monthly-pro-post-batch/llms.txt)

## Similar plans of other providers

- [Melissa, free, Monthly Top-off, GET /V4/WEB/GlobalEmail/doGlobalEmail](https://datacircle.dev/validate-email-apis/melissa/free-monthly-top-off-get-v4-web-globalemail-doglobalemail/llms.txt): $0.00 per 1,000, 50% complete, live
- [Minelead, free](https://datacircle.dev/validate-email-apis/minelead/free/llms.txt): $0.00 per 1,000, 50% complete, live
- [MailValidation.io, free, Free, POST /api/validate/](https://datacircle.dev/validate-email-apis/mailvalidation-io/free-free-post-api-validate/llms.txt): $0.00 per 1,000, 33% complete, live
- [MyEmailVerifier, free, 100 free credits daily, GET /verifier/validate_single/{email}/{API_KEY}](https://datacircle.dev/validate-email-apis/myemailverifier/free-100-free-credits-daily-get-verifier-validate-single-email-api-key/llms.txt): $0.00 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 2026-10-20.

- https://docs.mails.so/bulk
- https://docs.mails.so/intro
- https://docs.mails.so/response
- https://docs.mails.so/single
- https://mails.so
- https://mails.so/privacy
- https://mails.so/terms