Email list validation

Stop sending to emails that don’t exist

Upload your list or call the API and find out, before your next campaign, which addresses are valid, invalid, catch-all, disposable or risky. Fewer bounces, a sender reputation that stays intact, and a bill that only counts conclusive results.

Start with 100 free credits See pricing

Unknowns and duplicates are free
ZeroBounce-compatible API
100 free credits every month
Results deleted after 30 days

Check an email now

Syntax, domain, mail server and mailbox. No sign-up.

10 of 10 free checks left today.

emma.jones@gmail.comvalid
info@examplestore.comdo_not_mail
john@hotmial.cominvalid
sales@catchall-company.comcatch-all
olivia@yahoo.comunknown

How it works

From messy list to clean list in three steps

Nothing to install. Nothing is ever sent to your contacts.

01
Upload a list or call the API

A CSV or XLSX file with up to 1 million rows: just pick the email column. Or validate at sign-up, in real time, through the API.
02
We check every address

Syntax, typos, DNS, disposable and role-based lists, and a conversation with the recipient’s mail server, without sending a thing.
03
Download the results

A report by status, plus downloads of everything, only the valid addresses, or everything except the invalid ones. Duplicates are removed first and cost nothing.

What you get

A clear status for every address

The same statuses and sub-statuses as ZeroBounce, so if you already use it there’s nothing new to learn.

Valid
valid

The mailbox exists and the server accepted the recipient. Safe to send.
Invalid
invalid

The address can’t receive mail: no such mailbox, no mail server for the domain, a typo or bad syntax. Remove it: this is what causes bounces.

mailbox_not_foundno_dns_entriespossible_typofailed_syntax_check
Catch-all
catch-all

The domain accepts every address, so the mailbox can’t be confirmed. Send with care, ideally in smaller batches.
Unknown
unknown

The server didn’t give a conclusive answer (greylisting, anti-spam, timeout). You’re not charged: try again later.

No credit charged

greylistedantispam_systemtimeout_exceeded
Do not mail
do_not_mail

The address exists, but sending is risky: disposable, role-based (info@, sales@), toxic or on a suppression list.

disposablerole_basedtoxicglobal_suppression
Spam trap
spamtrap

Likely a spam trap: a single send can get your domain blocklisted.

possible_trap
Abuse
abuse

An address known for marking mail as spam and reporting senders.

API

Validate at sign-up, before a bad address gets into your database

One REST call returns the verdict as JSON. Batches of up to 100 addresses per request, and file uploads through the same API.

Key in the Authorization header or in ?api_key=, just like ZeroBounce
Suggested fixes for typos (did_you_mean)
Mailbox provider, MX and domain age in every response

Read the docs

request

# One address, in real time
curl "https://api.mailchecker.dev/v1/validate?email=emma@company.com" \
  -H "Authorization: Bearer mc_live_…"

response · 200

{
  "address": "emma.jones@gmail.com",
  "status": "valid",
  "sub_status": "",
  "account": "emma.jones",
  "domain": "gmail.com",
  "did_you_mean": null,
  "free_email": true,
  "role_based": false,
  "disposable": false,
  "mx_found": true,
  "mx_record": "gmail-smtp-in.l.google.com",
  "smtp_provider": "google",
  "domain_age_days": 11318,
  "processed_at": "2026-11-07T12:34:56Z",
  "domain_score": 100,
  "domain_reasons": ["dmarc_none", "free_email"]
}

Pricing

Pay only for conclusive results

1 credit per address. unknown results and duplicates are never charged.

Free

R$0

100 credits every month

Dashboard, list uploads and API
Resets monthly (doesn’t roll over)
No credit card required

Pay as you go

Credit packs

from R$99

2,000 credits · R$49.50 per 1,000

From 2,000 to 1 million credits
The bigger the pack, the lower the price per 1,000
Credits valid for 12 months

See all packs

Monthly subscription

up to 18% less

per credit, compared with packs

Credits added every month
Unused credits roll over while active
Cancel anytime

See subscriptions

Prices in Brazilian reais (for customers in Brazil). Show in US dollars.

FAQ

Before you ask

How do you know an email exists without sending anything?

We check the syntax, look for typos in the domain, query DNS for the MX record and talk to the recipient’s mail server just far enough for it to say whether it accepts that address. No message is ever sent. We also check lists of disposable, role-based and suppressed addresses.

What happens with “unknown” results?

They’re free. Some servers (Yahoo, AOL, some corporate anti-spam systems) won’t confirm recipients; when there’s no conclusive answer we return unknown and you keep the credit.

Do duplicate addresses count?

No. Duplicates within the same list or batch are removed before checking and never use a credit.

How much does it cost?

Every team gets 100 free credits a month. Beyond that, credit packs start at $19, as a one-off purchase or a monthly subscription. One credit = one verified address.

I already use ZeroBounce. Can I switch?

Yes. We use the same status and sub-status names and accept the key in the api_key parameter, just like ZeroBounce. For most integrations, switching means changing the base URL and the key.

What do you do with my lists?

Only check them for you. Verification results are kept for 30 days and then deleted. The team owner can export or delete the team’s data at any time.

Which files can I upload?

CSV or XLSX files with up to 1 million rows. Pick the email column, then download the full results, only the valid addresses or everything except the invalid ones.

Stop sending to emails that don’t exist

Check an email now

From messy list to clean list in three steps

Upload a list or call the API

We check every address

Download the results

A clear status for every address

Valid

Invalid

Catch-all

Unknown

Do not mail

Spam trap

Abuse