# ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses: Email verification API

> The email verification API lets you check whether an address can receive mail before you send to it.

ProspectAPIs's email verification API on its Free plan. It costs $0.00 per 1,000 emails. It returns 3 of the 6 key fields we check: Address, Deliverability, Confidence.
The cheapest of the 1,776 plans we rank by price is [treg, top-up from $10](https://datacircle.dev/validate-email-apis/treg/top-up-from-10/llms.txt). treg asks one provider after another until one answers. treg costs $0.00 per 1,000 emails on average. You pay $26.95 per 1,000 emails when no provider answers.

- This page: https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses
- [Best email verification API in 2026](https://datacircle.dev/best-email-verification-api.txt)
- Get it: https://prospectapis.com/pricing
- Its API docs: https://prospectapis.com/docs/reference/verify-emails
- Sold by: ProspectAPIs (https://prospectapis.com)
- Checked: 2026-10-26

## In the answer

- Completeness: 50%
- Address: ✓
- Deliverability: ✓
- Confidence: ✓

## Price

- $ per 1,000 emails: $0.00
- Per: result
- Billing: free

## Aggregators

- Aggregators: none

## Charges

- Also pays for: from the same budget: Search funding rounds · Read one funding round · Create a watchlist · Start a research brief · Clean a list · Start a verification job · Find an email address

## Not found

- $ per 1,000: $0.00

## Catch-all

- $ per 1,000: $0.00

## Bounce

- Bounce refund: the check's price, credited back once when an address reported valid bounces and is reported through POST /v1/email/outcomes within 30 days, up to 10% of the valid checks charged in those 30 days

## In their words

- Their pitch: The email verification API lets you check whether an address can receive mail before you send to it.

## Data

- Freshness: live
- Keep data: no limit
- Use data: Check anything that matters before you rely on it, and do not use the service as the only basis for a decision with legal or similar effect on a person. You may use what the API returns inside your own products and workflows. You may not resell or republish the data as a substantially similar dataset or API. [...] Use of the service must follow the acceptable use policy. [...] This policy sets the limits on how the service and its output may be used. [...] Use it for: Researching companies and the people who publicly represent them in a business role. Preparing for sales calls and writing outreach that is relevant to the recipient. Account research, territory planning and enriching business records with funding history. Do not use it to: Profile private individuals, or research anyone outside a business context. Harass, stalk, threaten or discriminate against anyone. Send messages that break anti-spam or marketing consent laws where the recipient is. Make decisions about employment, credit, insurance or housing for an individual. Resell or republish the data as a substantially similar dataset or API. Share API keys between unrelated parties, or create accounts to multiply free records. Probe, overload or work around the rate limits, billing or security of the service. Send the research API inputs you have no right to share, such as confidential third-party data in context.

## Plan

- Pay: $0
- You get: $1
- Enough for: 250 results, once
- Expires: never

## Rate limit

- Per second: 1
- Batch: 25

## Speed

- Answer: in the call

## The call

- You send: emails. Optional: emails[].first_name, emails[].last_name, depth, Idempotency-Key
- Method: POST
- Path: /v1/email/verify

## About the plan

- Plan: Free
- Who can get it: anyone, one account per person or company

## The 17 fields the plan's answer can hold

email address, status, reason, reason text, score, recommendation, charged, flags, SMTP code, catch-all tier, did you mean, mail provider, checked at, cache age days, results count, charged count, amount (USD)

## ProspectAPIs's plans (5)

- [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses/llms.txt): $0.00 per 1,000, 50% complete, live
- [ProspectAPIs, top-up from $10, Credit pack, any amount from $10 to $10,000, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-10-credit-pack-any-amount-from-10-to-10000-post-v1-email-verify-verify-email-addresses/llms.txt): $4.00 per 1,000, 50% complete, live
- [ProspectAPIs, top-up from $100, Top-up of $100 or more, +25% bonus credit, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-100-top-up-of-100-or-more-25-bonus-credit-post-v1-email-verify-verify-email-addresses/llms.txt): $3.20 per 1,000, 50% complete, live
- [ProspectAPIs, top-up from $500, Top-up of $500 or more, +60% bonus credit, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-500-top-up-of-500-or-more-60-bonus-credit-post-v1-email-verify-verify-email-addresses/llms.txt): $2.50 per 1,000, 50% complete, live
- [ProspectAPIs, top-up from $2,000, Top-up of $2,000 or more, +120% bonus credit, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/top-up-from-2000-top-up-of-2000-or-more-120-bonus-credit-post-v1-email-verify-verify-email-addresses/llms.txt): $1.818 per 1,000, 50% complete, live

## ProspectAPIs's calls for this API (4)

- `POST /v1/email/clean`: [ProspectAPIs, free, Free, POST /v1/email/clean](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-clean/llms.txt)
- `POST /v1/email/verify/jobs`: [ProspectAPIs, free, Free, POST /v1/email/verify/jobs](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-jobs/llms.txt)
- `POST /v1/email/verify`, Verify email addresses: [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses/llms.txt)
- `POST /v1/email/verify`, Verify email addresses, quick check: [ProspectAPIs, free, Free, POST /v1/email/verify, Verify email addresses, quick check](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses-quick-check/llms.txt)

## ProspectAPIs's APIs (4)

- [ProspectAPIs: company enrichment API pricing, 5 plans](https://datacircle.dev/company-enrichment-apis/prospectapis/free/llms.txt)
- [ProspectAPIs: email finder API pricing, 5 plans](https://datacircle.dev/find-email-apis/prospectapis/free/llms.txt)
- [ProspectAPIs: email verification API pricing, 5 plans, POST /v1/email/verify, Verify email addresses](https://datacircle.dev/validate-email-apis/prospectapis/free-free-post-v1-email-verify-verify-email-addresses/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, POST /v1/watchlists](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-post-v1-watchlists/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, GET /v1/funding/:id](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-get-v1-funding-id/llms.txt)
- [ProspectAPIs: cached company funding API pricing, 5 plans, GET /v1/funding](https://datacircle.dev/cached-company-funding-apis/prospectapis/free-free-get-v1-funding/llms.txt)

## ProspectAPIs: email verification API alternatives

- [Mailfloss, $244 monthly, Pro 135,000 credits/month, GET /v1/verify](https://datacircle.dev/validate-email-apis/mailfloss/244-monthly-pro-135000-credits-month-get-v1-verify/llms.txt): $1.807 per 1,000, 50% complete, live
- [Abstract API, $1,089 yearly](https://datacircle.dev/validate-email-apis/abstract-api/1089-yearly/llms.txt): $1.815 per 1,000, 33% complete, live
- [SafetyMails, $292 monthly](https://datacircle.dev/validate-email-apis/safetymails/292-monthly/llms.txt): $1.825 per 1,000, 33% complete, live
- [SendPulse, $458 monthly, Subscription 250000, Monthly, POST /verifier-service/send-single-to-verify/](https://datacircle.dev/validate-email-apis/sendpulse/458-monthly-subscription-250000-monthly-post-verifier-service-send-single-to-verify/llms.txt): $1.832 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 2026-10-26.

- https://prospectapis.com
- https://prospectapis.com/acceptable-use
- https://prospectapis.com/docs/email-verification
- https://prospectapis.com/docs/rate-limits
- https://prospectapis.com/docs/reference/verify-emails
- https://prospectapis.com/pricing
- https://prospectapis.com/terms