Email validation API
Email verification API that rejects bad addresses at signup.
curl -X POST https://api.trueguard.io/v2/email/validation \
-H "X-API-KEY: $YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"email":"founder@yourcompany.com"}'Start on the free tier
100 validations a month, no card.
Same production endpoint and response as the paid plan.
Get your free API keyRead the API documentationCheck one address now.
No key needed. 10 free checks a day, and the response is the same shape the endpoint returns.
Or try
Fake signups
Disposable addresses take a free-tier seat and skew every conversion number you report.
Sender reputation
Above a 2% bounce rate mailbox providers throttle you. Above 5% you land in spam.
Dead leads
Role accounts and rotted addresses sit in the CRM looking like pipeline.
What does the email verification API return?
Seven signals in one JSON response. Every field on every plan, including free.
Syntax
syntax.isValidMX records
isMxValidSMTP deliverability
isSmtpValidDisposable
isDisposableCatch-all
isCatchallRole-based
isRoleFree-mail provider
isFreeHow do I verify an email with one API call?
Three steps. Most teams integrate in an afternoon.
Sign up for a free API key
Call POST /email/validation
Read the JSON
Made for developers.
The same call in nine languages. Real working snippets. Paste, set the key, run. If your stack isn't listed, the curl translates cleanly.
curl -X POST https://api.trueguard.io/v2/email/validation \
-H "X-API-KEY: $YOUR_KEY" \
-H "Content-Type: application/json" \
-d '{"email":"founder@yourcompany.com"}'What does a typical JSON response look like?
This email address exists and can receive email.
{
"email": "realemail@gmail.com",
"rawEmail": "realemail@gmail.com",
"syntax": {
"isValid": true
},
"deliverability": {
"status": "safe",
"isSmtpValid": true,
"isMxValid": true,
"isCatchall": false,
"isInboxFull": false,
"isDeliverable": true,
"isDisabled": false,
"mxRecords": [
"alt2.gmail-smtp-in.l.google.com",
"gmail-smtp-in.l.google.com",
"alt4.gmail-smtp-in.l.google.com",
"alt1.gmail-smtp-in.l.google.com",
"alt3.gmail-smtp-in.l.google.com"
]
},
"domain": {
"name": "gmail.com",
"age": 11263,
"isLive": true,
"isRisky": false
},
"quality": {
"isDisposable": false,
"isFree": true,
"isRole": false,
"isSubaddress": false
}
}How accurate is real-time email verification?
Some checks are right every time. Others depend on the remote mail server cooperating.
<1%
False positive rate
Sub-1s
Median response time
100/month
Free API validations per month
$0.001
Per validation over quota
Syntax, MX, and disposable checks are deterministic. SMTP and catch-all detection depend on the destination mail server. If you need this at scale, the Standard plan returns the same answer with 50,000 monthly validations.
How much does the email verification API cost?
Three tiers. Free plan needs no card.
Standard
Popular$49.99 / month
50,000 validations / month
Overage: $0.001 per validation
Get your API keyPay for what you check. Cancel anytime. Overage is billed through Stripe at $0.001 per validation, the standard rate. Higher volumes are priced lower on request. One request to the validation endpoint is one validation; failed calls (4xx from your side) do not count.
What do teams use email verification for?
One bad address costs more than you think. It bounces, it lands you on blocklists, it sneaks a fake account into your free tier, or it sits in your CRM as a dead lead. Verification is one API call that pays back across every signup you accept and every email you send.
Stop fake signups at the form
Protect sender reputation
Clean an old list before you mail it
Qualify leads at capture
Frequently asked questions
Anything missing? Contact support or read the API reference.
What is an email verification API?
An email verification API is a REST endpoint that checks an email address in real time. Given an address, it returns whether the address is syntactically valid, has working MX records, accepts mail via SMTP, and whether the domain is disposable, catch-all, role-based, or a free provider. Call it from your backend at signup, form submit, or before a campaign sends.
How fast is real-time email verification?
Trueguard's API targets Sub-1s median response time. Slow SMTP servers push response times higher because the check waits on the remote mail server.
What's the difference between syntax validation and SMTP verification?
Syntax validation checks the email matches the RFC 5322 grammar. It catches typos. SMTP verification opens a connection to the destination mail server and checks the address is accepted without sending a message. Syntax is deterministic. SMTP is probabilistic.
Can the API detect disposable email addresses?
Yes. Trueguard maintains a continuously updated registry of disposable email domains. The same dataset powers /disposable-emails. The response includes a disposable flag plus enrichment like when the domain was first seen.
Do you support catch-all detection?
Yes. Catch-all domains accept any address at the domain, so SMTP cannot prove a specific mailbox exists. The API returns the isCatchall flag and a status of risky, unless a second check that does not use SMTP confirms or rules out the mailbox. Then the status is safe or invalid.
What does the API cost at scale?
The Standard plan is $49.99 a month and includes 50,000 validations. Overage is $0.001 per validation, billed through Stripe.
Is there a free tier with no credit card?
Yes. 100 validations a month, no card, no trial expiry. The free tier runs the production endpoint. Same response shape, same latency, same accuracy.
How is this different from Trueguard's main fraud-detection product?
The email verification API is a standalone product. You can buy it without using Trueguard's main verification flow. If you already run Trueguard for fake-signup prevention, you can chain email validation as one more input. Same API key, separate meter.
Stop bouncing. Stop guessing.
100 validations a month, free, no card. Switch when you outgrow the quota, not when you outgrow the demo.
Get your free API keyNo credit card required.
