FirstSales pricing and alternatives: cached email verification API

FirstSales's site llms.txt Best cached email verification API in 2026

33% complete: 2 of the 6 key fields we checkSee the 6 fields

$0.00per 1,000 emails

Plan: Public, no key FirstSales's only plan

FreePublic, no key$0.00 per 1,000

Call: POST /api/v1/email/validate FirstSales's only call

POST /api/v1/email/validateFree$0.00 per 1,000

About this item

Stored. FirstSales may skip the mail server and answer from data it keeps. FirstSales doesn't say how old the data is.
2 of the 6 key fields we check. Deliverability, Company.
Nothing to pay. FirstSales limits how many calls you get, but doesn't say how many.
One call. You send email to POST /api/v1/email/validate. The call returns whether the address takes mail.
Who can get it: anyone at least 18 years old, for B2B commercial use only. Keep data: no limit. Use data: with conditions.

FirstSales: cached email verification API alternatives

We list other providers' plans closest to this plan in price per 1,000 emails. Each plan in the table gives stored data, not live data, like this plan.

	This planFirstSales, free	graph8, free	KaijuVerifier, free, Free, POST /api/v1/jobs	Strale, free, trial credits, POST /v1/do, Bulk Email Validation	APIVerve, free
$ per 1,000	$0.00	$0.00	$0.00	$0.00	$0.00
Completeness	33%	33%	50%	50%	50%
Billing	free	free	free	free	free
Pay	$0	$0	$0	$0	$0
Enough for	not published	not published	100 results a month	not published	10 calls a month
Freshness	stored	stored	stored	stored	stored (MX valid, MX record, null MX, can receive mail, has SPF, has DMARC: live)
Who can get it	anyone at least 18 years old, for B2B commercial use only	verified companies with a work email (personal addresses such as Gmail are not accepted), for internal business purposes	anyone	anyone who signs up, one trial credit per email address	anyone 13 or over (under 18 only with the permission of a parent or legal guardian)

Sources

From each provider's own pricing page and docs, and from what providers tell us. We read this row from these pages on 2026-10-23.

Product details

The key fields this plan's answer can hold, then each filled column in its row on the sheet.

Address, not in the answer
Deliverability
Confidence, not in the answer
Name, not in the answer
Place, not in the answer
Company

Price
$ per 1,000	$0.00
Billing	free

Aggregators
Aggregators	none

Charges
Per	call
Also pays for	Score an email domain for disposable/temporary-mailbox risk · Detect whether a domain accepts mail to any mailbox (catch-all) · Run one specific DNS/email-authentication/security check against a domain · Look up and validate a domain's DKIM record · Run SPF, DKIM, DMARC, and MX checks together with a confidence score · Reverse-DNS (PTR) lookup for an IPv4 address, with forward-confirmation · Get a domain's registration age and expiration via RDAP · Fetch every DNS record type for a domain in one call · Discover subdomains via Certificate Transparency logs · Score email content for spam-trigger risk · Score and improve a cold-email subject line · Grade a full cold-email draft across 8 deliverability/effectiveness dimensions · Score and improve a cold-email body · Detect and score personalization signals in cold-email content · Create a temporary test inbox · Read the received emails for a test inbox · List public tutorials · Get one tutorial by slug · Service health check

Not found
$ per 1,000	$0.00

In their words
Their pitch	Check email addresses, DNS records and cold email copy from your own code, with no key.

Data
Freshness	stored
Keep data	no limit
Use data	You agree to use the Service only for lawful B2B commercial outreach, and to follow all laws and regulations that apply. You must not do any of the following: [...] Resell, sublicense or white-label the Service, or make it available to anyone else, without written permission from FirstSales first. [...] Use automated scripts, bots or other tools to put artificial load on, overload or interfere with the Service's systems or the systems of mailbox providers. [...] Get around or turn off any rate limits, sending caps or security controls built into the Service.

Plan
Pay	$0

Rate limit
Per second	0.33
Batch	1

Speed
Answer	in the call

The call
You send	email
Method	POST
Path	/api/v1/email/validate

About the plan
Plan	Public, no key
Who can get it	anyone at least 18 years old, for B2B commercial use only

The 11 fields the plan's answer can hold

valid, domain, domain exists, has MX record, reserved domain, disposable, free provider, MX records, MX priority, error, message