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Contact Services

API Bulk

Email Validation & Verification API

Multi-layer email validation — syntax, DNS, SMTP deliverability, disposable detection, and quality scoring. Catch bad addresses before they bounce.

5 Layers
Validation Depth
SMTP
Deliverability Check
Score
Quality Rating
Bulk
CSV Upload

An email address can pass regex validation and still be completely useless. The domain might not exist. The mailbox might be full. The address might be a disposable throwaway that'll vanish in ten minutes. If you're only checking syntax, you're letting bad data in.

The Checkify email validation endpoint goes five layers deep. It checks RFC syntax, resolves MX records via DNS, probes the SMTP server for deliverability, detects disposable and temporary email providers, flags free providers and role accounts (like info@ or noreply@), and returns an overall quality score.

For marketing lists and CRM imports, use the bulk endpoint to validate thousands of addresses in a single job. Bad addresses are flagged so you can remove them before your next campaign — protecting your sender reputation and reducing bounce rates.

The cost of bad email data adds up fast. Most email service providers charge per subscriber, so every dead address on your list is money wasted. Worse, if your bounce rate climbs above 2–3%, providers like Gmail and Outlook start treating your sending domain as suspicious. Your emails land in spam, open rates drop, and your marketing team wonders why their last campaign underperformed. Validating before you send is cheaper than recovering a damaged sender reputation.

The disposable detection layer is especially useful for SaaS signups. Services like Guerrilla Mail and Mailinator let anyone create a throwaway address in seconds — great for the user who wants to test your product without commitment, terrible for your activation metrics and support workflows. Flag those at registration and you'll get a much clearer picture of real user intent. For validating the other half of contact data, the phone validation endpoint handles number formatting, carrier detection, and line type classification.

What you get

Endpoint capabilities and technical details.

RFC syntax validation

Checks the email format against RFC 5322 standards. Catches common formatting errors like double dots, missing @ symbols, and invalid characters.

MX record lookup

Resolves the domain's MX records via DNS. If the domain doesn't have a mail server, the address can't receive email — regardless of what the syntax says.

SMTP deliverability

Probes the mail server to check whether the specific mailbox exists and can accept messages. Detects full inboxes, disabled accounts, and non-existent mailboxes.

Disposable email detection

Flags addresses from disposable/temporary email providers like Guerrilla Mail, Tempail, and Mailinator. These addresses are often used for spam or one-time signups.

Free provider flag

Identifies addresses from free email providers (Gmail, Yahoo, Outlook, etc.). Useful for B2B workflows where you want to prioritise business domain addresses.

Role account detection

Flags generic role accounts like admin@, info@, noreply@, and support@. These often don't belong to a specific person and may not be monitored.

Quality score

Returns a score from 0 to 1 indicating overall email quality. Combines all validation layers into a single number you can threshold against.

Bulk processing

Upload a CSV of email addresses for batch validation. Clean your entire contact list in one job.

Why use this endpoint

Lower bounce rates

Remove undeliverable addresses before sending. Fewer bounces means better sender reputation, better inbox placement, and lower email service costs.

Cleaner signups

Validate email addresses on registration forms in real time. Block disposable addresses and catch typos before they create dead accounts.

Protected sender reputation

High bounce rates and spam trap hits damage your sending domain's reputation. Validating addresses before campaigns keeps your deliverability metrics healthy.

Built for your industry

Common use cases across industries that rely on validated Australian data.

Marketing & CRM

Clean email lists before campaigns. Remove invalid, disposable, and role addresses to improve deliverability and reduce bounce rates.

SaaS & Apps

Validate email addresses at registration. Block disposable providers to reduce fake signups and improve user quality.

E-commerce

Verify customer email addresses at checkout to ensure order confirmations and shipping updates reach the right inbox.

Financial Services

Email verification as part of customer onboarding and KYC workflows. Ensure contact details are valid and deliverable.

Recruitment

Validate candidate email addresses before sending interview invitations and offer letters.

Data Integrity

Trusted data, transparent pricing

Email validation combines local syntax and DNS checks with an external deliverability service. The external service probes the recipient's mail server to check mailbox existence — it does not send actual emails. No message content is transmitted during validation.

Source: DNS + SMTP probing

Transparent Pricing

How search units work

Checkify uses a simple unit-based model. Each paid API call costs 1–3 search units depending on the endpoint. Your monthly plan includes a set number of units — use them on any endpoint, any time. No hidden fees.

This endpoint: 1 unit per call

1 unit deducted per successful API call.

Estimate your monthly usage
Developer Corner

Ready to integrate?

One REST endpoint, JSON responses, Bearer token auth. No SDK required — just HTTP. Check the full docs for parameters, response schemas, and error codes.

Request curl
curl -H "Authorization: Bearer ck_prv_..." \
  "https://checkify.com.au/api/v1/[email protected]"
Response JSON
{
  "email": "[email protected]",
  "valid": true,
  "format": { "valid": true },
  "dns": { "valid": true },
  "deliverable": true,
  "catchAll": false,
  "score": 0.95,
  "free": true,
  "disposable": false,
  "role": false
}

Frequently asked questions

Does this actually send an email?
No. The SMTP check probes the mail server to verify the mailbox exists. No message is sent and the recipient is not contacted.
What does the quality score mean?
The score (0–1) combines all validation layers — syntax, DNS, deliverability, and risk factors like disposable or catch-all domains. Higher is better. You decide the threshold for your use case.
Can it detect catch-all domains?
Yes. The catch_all flag indicates whether the domain accepts email to any address (even non-existent ones). This is common with small business mail servers and makes individual mailbox verification less reliable.
Does it work for non-Australian emails?
Yes. Email validation works for any email address worldwide — it's not limited to Australian domains.
Can I validate emails in bulk?
Yes. Upload a CSV with an "email" column through the bulk endpoint. Available on Business and Enterprise plans.

Start validating in minutes

Free to try. No credit card required. Full API access from day one.