What counts as a validation?

Each email address checked through the Mailchk API counts as one validation. Cached results for the same email within 24 hours do not count against your limit.

Can I upgrade or downgrade at any time?

Yes, you can change your Mailchk plan at any time. Upgrades take effect immediately, and downgrades take effect at the start of your next billing cycle.

Is there a free trial for paid plans?

Yes, all paid Mailchk plans come with a 14-day free trial. No credit card required to start.

What happens if I exceed my monthly limit?

You will receive a notification when you reach 80% and 100% of your limit. If you have credit balance, validations will automatically use your credits as overflow. You can also upgrade your plan for a higher monthly limit.

Credits are a pay-as-you-go option. 1 credit = 1 email validation. Buy a credit pack any time — credits are used automatically when your monthly subscription limit is reached. Credits expire 1 year from your most recent purchase, and each new purchase extends the expiry date.

What does the Mailchk Enterprise plan include?

Mailchk Enterprise plans are fully customised to your needs. This includes unlimited validations, advanced validation features (catch-all detection, mailbox existence checking, greylisting detection), dedicated infrastructure, custom SLAs, an account manager, SSO, and invoice-based billing.

Email List Validation

Upload. Validate. Download.

Clean your email list in minutes. Upload a CSV, we validate every address with multi-layer checks, and you download a list ready for high deliverability.

Start Free View Pricing

Starting at $0.001 per email. 200 free validations included.

Drop your CSV file here

or click to browse

Features

Built for Scale

Everything you need to clean, analyze, and export email lists of any size.

Syntax Validation

Catches formatting errors, missing @ signs, invalid characters, and malformed addresses.

DNS & MX Lookup

Verifies the domain exists and has valid mail exchange records configured to accept email.

Disposable Detection

Identifies temporary and throwaway email services like Mailinator, Guerrilla Mail, and 10MinuteMail.

Typo Detection

Catches common misspellings like gmial.com, outlok.com, and yaho.com before they bounce.

Role Account Detection

Flags generic addresses like info@, admin@, and support@ that rarely belong to real people.

Risk Scoring

Every email gets a risk score — low, medium, high, or critical — so you can decide what to keep.

Step by Step

How It Works

Upload Your List

Upload a CSV or TXT file. We auto-detect the email column — no manual mapping needed.

Multi-Layer Validation

Every email is checked for syntax, DNS, MX records, disposable domains, typos, and more.

Review Results

See a detailed breakdown with risk scores, status categories, and flagged issues.

Download Clean List

Export your cleaned list as CSV, filtered by status. Ready to import into any ESP.

Features

Built for Large Lists

Everything you need to clean, analyze, and export email lists of any size.

Smart Column Detection

Automatically finds the email column in your CSV — no matter what the header is called.

Automatic Deduplication

Duplicate emails are removed before verification starts, saving your credits automatically.

Real-Time Progress

Watch validation happen in real-time with live counters and estimated completion times.

Flexible Exports

Download results filtered by status — valid only, invalid only, or the full annotated list.

Up to 1M Emails

Process lists from a handful of addresses up to 1 million emails in a single upload.

Pay Per Check

No subscriptions required. Buy credits and use them whenever you need — they never expire.

FAQ

Common Questions

We accept CSV and TXT files. For CSVs with multiple columns, we automatically detect which column contains email addresses.

Speed depends on list size. A list of 1,000 emails typically completes in under 2 minutes. Larger lists of 100k+ emails may take 15-30 minutes.

Individual files can be up to 10MB. We support lists with up to 1 million unique email addresses per upload.

Duplicates are automatically removed before validation begins. You only pay for unique emails, and we show you the duplicate count.

No. You can use pay-as-you-go credits for bulk validation. We also offer monthly plans with included validations if you prefer.

Yes. When downloading results, you can filter by status — valid only, invalid only, risky only, or the complete annotated list.

Don't just take our word for it

See why teams rely on Mailchk to keep their email lists clean

"Mailchk reduced our fake signups by 89%. The API is incredibly fast and the documentation is excellent."

Noel S

CTO, MyBrands Group

"We integrated Mailchk in under an hour. It catches disposable emails that other services miss."

Stephen M

Lead Developer, TRTCompare

"Finally, a solution that actually works. Our email deliverability improved by 40% after implementing Mailchk."

Michael G

Product Manager, Evernu

"The real-time validation is a game changer. No more wasted resources on fake accounts."

Joe S

Founder, Moojority

"Mailchk handles our 100k+ daily validations without breaking a sweat. Incredible performance."

Katie E

DevOps Lead, CVS

"Switched from a competitor and never looked back. Better accuracy, better pricing, better support."

Brendan O

Tech Lead, CardGenr