Email Deliverability Verification and Domain Health API

API ID 13100

Check any domain's email deliverability & health (SPF, DMARC policy, MX provider, WHOIS domain age, hosting, disposable/catch-all, 0-100 score) and verify any email address (SMTP, MX, disposable, role, catch-all). Live data, not a stale database.

605 ms avg response

API Documentation

Endpoints

Request

Verify domains with DNS, MX, SPF, DMARC, registration, infrastructure, and security checks, delivering trust scores and validation insights instantly.

Endpoint ID: 26548
GET https://zylalabs.com/api/13100/email+deliverability+verification+and+domain+health+api/26548/domain+deliverability+and+health+check
INPUT PARAMETERS

Domain Deliverability and Health Check — Endpoint Features

Object Description
domain Required The domain to analyze (an email address also works — the domain is extracted). e.g. stripe.com

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

domain
API EXAMPLE RESPONSE
JSON
{"domain":"stripe.com","score":97,"grade":"high","email":{"provider":"Google Workspace","has_mx":true,"spf":{"present":true,"policy":"soft"},"dmarc":{"present":true,"policy":"reject"},"is_disposable":false},"registration":{"registrar":"SafeNames Ltd.","created":"1995-09-12T04:00:00Z","expires":"2027-09-11T04:00:00Z","age_days":11255},"infra":{"hosting":"AWS Route 53","ips":["198.202.176.161","198.137.150.161"],"has_valid_cert":true},"dns":{"a":["198.202.176.161","198.137.150.161"],"aaaa":[],"mx":["aspmx.l.google.com","alt2.aspmx.l.google.com","alt1.aspmx.l.google.com","aspmx3.googlemail.com","aspmx2.googlemail.com"],"ns":["ns-1087.awsdns-07.org","ns-1882.awsdns-43.co.uk","ns-423.awsdns-52.com","ns-705.awsdns-24.net"],"txt":["asv=8de0c1a866b958297e22a36216e594a6","whimsical=253112f9add9790f3a27b9d9893626451fc4cda1","v=MCPv1; k=ed25519; p=WMeka0C1fIH9HQLMtsSM9DD9cM6Bz6Wz34mHnK86UcM=","facebook-domain-verification=m7id9rt8ehlgcg9tt2yggbsi6gro7i","canva-site-verification=xLypn0D9XANRy-lbwcMfHA","google-site-verification=qjP3OAiraClha_40cX9Z9FrG5q3O_0InXSamXOswY-s","google-site-verification=hPfjsDwiisKJ4RP1ExOst9gAOD_0P8Q7-kxdcKUvEcc","apple-domain-verification=8kIS0gmJTvILWQuI","docusign=4c9f5602-1c19-4e4c-bde7-77dc4b9ea8a0","docusign=4a93db58-af07-4632-a881-b569d41a6c57","h1-domain-verification=KhpNX9YNAc7bX95agGvFsPPKbYTVe1KC6xj7P1zKZrRzxcuS","fastly-domain-delegation-3c9tdnjzdwy7wfffvyyy-786084-2024-07-08","cursor-domain-verification-vncvvm=D0NzeIDbQa8PPgIf1ukp9UPiu","atlassian-domain-verification=upLp21qQgja1aHG2gnAb1AmXRqb/zG0UK1a0n3zTSXZg5DgOSttR3i5uzA3T9Cdk","docker-verification=ccde1a0d-8d2c-44b5-9d20-6c4e19113fc9","MS=ms80697640","_mphpl78cv3thhugki4dkknlukgj1du6","google-site-verification=NLkFgZLHeVMVYlR3t1UZC9_1LzmqCAefJyNDs6ZQqBA","z4mthhzk10l6qc0rg4211mnnppkh2y5b","anthropic-domain-verification-zk7x9c=QfN52ECybLPUWh51R9pKF0QO3","neat-pulse-domain-verification-8GMn8nv=36eba03d-345e-421a-a823-d6d1f28938a4","google-site-verification=pmz8ueKvWMPxNlwUDcVroF91-tq6I9VM6wSO_0i7-wc","postman-domain-verification=c3b168067b16085c452b04b643ae1000079b095e383b53d1074e409b0e600b6265e1c7963beca1ca87cc63c381dcea332544c92c919651e4cda69f9a6303079c","v=spf1 ip4:198.2.180.60/32 ip4:13.111.2.227/32 include:spf1.stripe.com include:greenhouse-outbound-mail.stripe.com include:_spf.qualtrics.com ~all","00D50000000JV6w=1TBTQ0000000CIv;00DDn000000HWol=1TBVY00000002Hx;00D4x000003vxGL=1TBPQ00000008Tp;00Dfn00000BUlWD=1TBan0000000LPR","edcbf4c7-b604-457b-870e-1b05f655e769","google-site-verification=PrlpJHdk11CIkPsiXoHEAJevWHAk39JRFAqVSe9l7n0","liveramp-site-verification=7gyFkTwGYsvgd7IUQwyAOfImETwR06wgKjKiXq90KEY","elevenlabs=NpcIkVJW_8Vyd2gLKzPviuaU1g5rz83KiWQQ3sWKGtI","stripe-verification=82ce82470fb8324e19fa65abdb6fd370da5a8f90bba09712f259760f625d0790","google-site-verification=ZgGi2-xDdfnaWxdfjn5AqtUS11jKWqSXAV_EHODFzdE"],"cname":[]},"subdomains":["answers.stripe.com","api-e1.stripe.com","api-e2.stripe.com","api-nw1.stripe.com","api-nw2.stripe.com","api-nw3.stripe.com","api-tls12.stripe.com","api-w1.stripe.com","api-w2.stripe.com","api.stripe.com","auth.stripe.com","bfcm.stripe.com","bofa-enhanced-issuer-network.stripe.com","bom.corp.stripe.com","book.stripe.com","button.stripe.com","buy.fastly.cdn.stripe.com","buy.stripe.com","cdn.qa-files.stripe.com","checkout-api-modelt.stripe.com","checkout.fastly.cdn.stripe.com","checkout.stripe.com","cmh.corp.stripe.com","codeint.stripe.com","commerce-mcp.stripe.com","connect-js.stripe.com","connections-auth.stripe.com","connections-barclays.stripe.com","connections-sandbox.stripe.com","corp.stripe.com","cpe.corp.stripe.com","cpe.qa.corp.stripe.com","crypto-js.stripe.com","dashboard-admin.stripe.com","dashboard.stripe.com","donate.stripe.com","east.corp.stripe.com","edge-book.stripe.com","edge-button.stripe.com","edge-buy.fastly.cdn.stripe.com","edge-buy.stripe.com","edge-checkout.fastly.cdn.stripe.com","edge-checkout.stripe.com","edge-donate.stripe.com","edge-invoice.fastly.cdn.stripe.com","edge-invoice.stripe.com","edge-js.fastly.cdn.stripe.com","edge-js.stripe.com","files-cdn.stripe.com","fl.corp.stripe.com","fl.qa.corp.stripe.com","g5-api.stripe.com","git.corp.stripe.com","hoth.stripe.com","invoice.fastly.cdn.stripe.com","invoice.stripe.com","ipaddr-3ds.stripe.com","irc.stripe.com","irs-ides-client.stripe.com","jira.corp.stripe.com","jira.qa.corp.stripe.com","js.fastly.cdn.stripe.com","js.stripe.com","jss.corp.stripe.com","jss.prod.corp.stripe.com","jss.qa.corp.stripe.com","local.corp.stripe.com","m.stripe.com","manage.stripe.com","newapi.stripe.com","northwest.corp.stripe.com","not-a-git.corp.stripe.com","panoplied-respect.stripe.com","partner-ideal-prod.stripe.com","partner-ideal-qa.stripe.com","pay-by-bank.stripe.com","pdx.corp.stripe.com","preprod-bfcm.stripe.com","preprod-button.stripe.com","preprod-checkout.stripe.com","preprod-connect-js.stripe.com","preprod-connections-sandbox.stripe.com","preprod-crypto-js.stripe.com","preprod-g5-api.stripe.com","preprod-invoice.stripe.com","preprod-js.stripe.com","preprod-profile.stripe.com","preprod-public-goods.stripe.com","preprod-secure-files.fastly.cdn.stripe.com","preprod-secure-files.stripe.com","preprod-status.stripe.com","preprod-terminal-statics.stripe.com","preprod-trust.stripe.com","prod-connections-bofa.stripe.com","prod-connections-chase.stripe.com","prod-connections-citi-payload.stripe.com","prod-connections-citi.stripe.com","prod-network-citi-payload.stripe.com","prod-network-citi.stripe.com","prod-partner-amex-east-asia-sponsored-merchant.stripe.com","prod-partner-hdfc.stripe.com","profile.stripe.com","public-goods.stripe.com","qa-bfcm.stripe.com","qa-bom.corp.stripe.com","qa-book.stripe.com","qa-button.stripe.com","qa-buy.stripe.com","qa-checkout.stripe.com","qa-cmh.corp.stripe.com","qa-connect-js.stripe.com","qa-connections-bofa.stripe.com","qa-connections-chase.stripe.com","qa-connections-citi-payload.stripe.com","qa-connections-citi.stripe.com","qa-connections-sandbox.stripe.com","qa-crypto-js.stripe.com","qa-donate.stripe.com","qa-east.corp.stripe.com","qa-edge-testing.stripe.com","qa-files-cdn.stripe.com","qa-g5-api.stripe.com","qa-invoice.stripe.com","qa-js.stripe.com","qa-jwt-connections-barclays.stripe.com","qa-m.stripe.com","qa-network-citi-payload.stripe.com","qa-network-citi.stripe.com","qa-northwest.corp.stripe.com","qa-pandora-v2-test.stripe.com","qa-partner-amex-east-asia-sponsored-merchant.stripe.com","qa-partner-hdfc.stripe.com","qa-pdx.corp.stripe.com","qa-profile.stripe.com","qa-public-goods.stripe.com","qa-secure-files.fastly.cdn.stripe.com","qa-secure-files.stripe.com","qa-status.stripe.com","qa-terminal-statics.stripe.com","qa-trust.stripe.com","qa.corp.stripe.com","revoked.stripe.com","sandbox-acs.stripe.com","secure-files.fastly.cdn.stripe.com","secure-files.stripe.com","sessions.stripe.com","static.stripe.com","status.stripe.com","stripe-credit-ui.stripe.com","stripe.com","support.stripe.com","terminal-statics.stripe.com","test-digicert-cert.stripe.com","trust.stripe.com","verificator.stripe.com","www.api.stripe.com","www.sessions.stripe.com","www.stripe.com"],"subdomain_count":158,"fetched_at":"2026-07-07T02:47:59.061Z"}
Domain Deliverability and Health Check — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/13100/email+deliverability+verification+and+domain+health+api/26548/domain+deliverability+and+health+check?domain=stripe.com' --header 'Authorization: Bearer YOUR_API_KEY' 


    
Request

Verify email addresses with syntax, SMTP, MX, catch-all, disposable, and deliverability checks, returning confidence scores and validation status instantly.

Endpoint ID: 26549
GET https://zylalabs.com/api/13100/email+deliverability+verification+and+domain+health+api/26549/verify+email+address
INPUT PARAMETERS

Verify Email Address — Endpoint Features

Object Description
email Required The email address to verify. e.g. [email protected]

Free test requests remaining: 3 of 3.


INPUT PARAMETERS

email
API EXAMPLE RESPONSE
JSON
{"email":"[email protected]","status":"risky","deliverable":true,"score":75,"checks":{"syntax":true,"mx":true,"disposable":false,"role_account":false,"free_provider":false,"catch_all":true,"smtp":true},"did_you_mean":null,"verified_at":"2026-07-07T14:32:31.419Z","billed":true}
Verify Email Address — CODE SNIPPETS

curl --location --request GET 'https://zylalabs.com/api/13100/email+deliverability+verification+and+domain+health+api/26549/[email protected]' --header 'Authorization: Bearer YOUR_API_KEY' 


    

API Access Key & Authentication

After signing up, every developer is assigned a personal API access key, a unique combination of letters and digits provided to access to our API endpoint. To authenticate with the Email Deliverability Verification and Domain Health API simply include your bearer token in the Authorization header.

Headers
Header Description
Authorization Required Should be Bearer access_key. See "Your API Access Key" above when you are subscribed.

No long-term commitment. Upgrade, downgrade, or cancel anytime. Free Trial includes up to 50 requests.

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Trusted by leading companies

Overview

Check any domain's email deliverability and overall domain health in a single API call before you send an email, add it to your CRM, or trust a new signup. Simply send a domain and receive a complete assessment in milliseconds, including email deliverability, domain health, and a unified score from 0 to 100 that makes it easy to decide whether the domain is trustworthy.

The API identifies the email provider such as Google Workspace, Microsoft 365, Zoho, or a self hosted server, verifies SPF and DMARC configurations while returning the actual DMARC policy, checks MX records, and confirms whether the domain is properly configured to send and receive email. It also analyzes domain age, registrar, expiration, TLS certificate validity, hosting provider, CDN, disposable and catch all status, raw DNS records, and subdomains to provide a complete picture of the domain's legitimacy and technical health. Scores between 70 and 100 indicate a healthy, established, and properly configured domain that is safe to email, scores between 40 and 69 suggest a working domain with some potential concerns such as weak email security or a young registration, and scores below 40 highlight domains that are new, disposable, or misconfigured and should be verified before use.

This helps cold email teams avoid wasted sends and protect deliverability, enables lead generation platforms to qualify domains before they enter a CRM, allows applications to block fake or disposable signups in real time, and simplifies deliverability and security audits by validating critical email authentication settings. Unlike other solutions that require multiple services, this API combines domain health, email authentication, mail infrastructure, and trust scoring into one live response while exposing the real DMARC policy instead of a simple yes or no result. It is also designed for AI agents, allowing Claude Code, Cursor, MCP clients, AI SDRs, outreach bots, and automation platforms to understand and use every endpoint directly through machine readable documentation without requiring custom integration logic.

Email Deliverability Verification and Domain Health API FAQs

The "Domain Deliverability and Health Check" endpoint returns data on domain health, email deliverability, and a score from 0 to 100. The "Verify Email Address" endpoint provides information on the email's deliverability status, risk level, and various checks like syntax and MX records.

Key fields include "domain," "score," "provider," "has_mx," "spf," "dmarc," "registration," and "infra" for domain checks. For email verification, fields include "email," "status," "deliverable," and "checks" detailing various validation results.

The response data is structured in JSON format, with nested objects for detailed information. For example, the domain check response includes sections for email details, registration info, and infrastructure, while the email verification response includes checks and status.

The domain endpoint provides insights on SPF, DMARC, MX records, domain age, and hosting details. The email verification endpoint checks for syntax, MX records, disposable status, and role accounts, offering a comprehensive view of email validity.

Data accuracy is ensured through live checks against current DNS records and email configurations, rather than relying on a static database. This allows for real-time assessments of domain health and email deliverability.

Typical use cases include validating domains before sending emails, qualifying leads for CRM integration, blocking disposable signups in applications, and conducting security audits on email configurations.

Users can customize requests by specifying the domain or email address they wish to check. The API processes these inputs to return tailored results based on the provided parameters.

Users can expect scores between 0-100, with higher scores indicating better domain health. For email verification, statuses like "deliverable" or "risky" provide quick insights into email validity, helping users make informed decisions.

The email verification endpoint checks for syntax validity, MX record presence, disposable status, role account identification, free provider usage, catch-all status, and SMTP connectivity. This comprehensive assessment helps determine the deliverability and risk level of the email address.

The domain health score ranges from 0 to 100, based on factors such as SPF and DMARC configurations, MX record validity, domain age, and hosting details. Higher scores indicate better email deliverability and domain trustworthiness.

The "status" field in the email verification response indicates the risk level associated with the email address. Possible values include "deliverable," "risky," or "undeliverable," helping users assess whether to proceed with communication.

No, each request to the API is designed to check one domain or email address at a time. Users must send separate requests for each domain or email they wish to verify.

The domain registration information includes the registrar name, creation date, expiration date, and the age of the domain in days. This data helps assess the legitimacy and stability of the domain.

The "grade" field categorizes the domain's health based on its score. Grades such as "high," "medium," or "low" provide a quick visual cue for users to gauge the domain's trustworthiness and email deliverability.

The API can analyze any domain, including those associated with popular email providers like Google Workspace and Microsoft 365, as well as self-hosted servers. It also identifies disposable and catch-all domains.

If a domain has missing or incomplete data, the API will still return available information, but the score may reflect potential risks. Users should interpret lower scores as indicators of possible issues with the domain's configuration or legitimacy.

General FAQs

To obtain your API key, first sign in to your account and navigate to the API you want to use. From the API's Pricing section, choose a plan and complete the subscription process. Once subscribed, return to the API page and you will see your API Access Key displayed at the top of the documentation page. You can use this key to authenticate your requests.

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