Verify email addresses with real SMTP verification. GTMData connects to the mail server and confirms the mailbox exists — no email is ever sent. Catch-all detection, disposable blocking, and provider identification included in every call.
100 free credits. No credit card required. Validate up to 400 emails free.
Three steps to verified email data. No email is ever sent to the recipient — we verify at the SMTP protocol level.
Make a single API call with the email address you want to validate. Pass one email or thousands in a batch request.
GTMData connects to the recipient mail server and performs a real SMTP handshake to check if the mailbox exists. No email is ever sent.
Receive a validation status (valid, invalid, catch-all, or unknown), the email provider, whether the domain is disposable, and a confidence score.
A single POST request returns the validation status, email provider, disposable flag, and more. Integrate in minutes with any language.
curl -X POST https://api.gtmdata.co/v1/validate \
-H "Authorization: Bearer gtm_live_..." \
-H "Content-Type: application/json" \
-d '{"email": "tim@apple.com"}'
{
"email": "tim@apple.com",
"status": "valid",
"provider": "google",
"is_disposable": false,
"is_catch_all": false,
"mx_records": ["aspmx.l.google.com"],
"confidence": 0.99,
"credits_charged": 0.25,
"cached": false,
"response_time_ms": 847
}Most email validators rely on regex patterns and DNS lookups. GTMData performs real SMTP verification combined with proprietary intelligence to deliver results you can trust.
We go beyond regex and DNS checks. GTMData connects to the mail server and performs a full SMTP handshake to verify the mailbox actually exists. This catches typos, deactivated accounts, and non-existent addresses that syntax-only validators miss.
Catch-all domains accept mail for any address, making validation tricky. GTMData uses SMTP timing analysis and convention matching to determine whether an email on a catch-all domain is likely real or fabricated.
Every validation enriches our domain intelligence cache. Previously validated emails return results in under 5 milliseconds, so your application stays fast even at high throughput.
Our continuously updated database flags disposable and temporary email providers like Guerrilla Mail, Mailinator, and thousands more. Stop fake signups and protect your sender reputation before they start.
Know whether an email is hosted on Google Workspace, Microsoft 365, Zoho, or another provider. Use this intelligence to tailor your deliverability strategy, segment audiences, or route outbound sequences by provider.
Invalid emails and unknown results are free. You are only charged credits when we return a verified valid or catch-all result. This keeps your costs predictable and aligned with the value you receive.
Every email validation returns one of five status types. You are only charged for results that provide actionable value.
| Status | Credits | Description |
|---|---|---|
| valid | 0.25 | The mailbox exists and accepts mail. Safe to send. |
| catch-all | 0.25 | The domain accepts all addresses. We provide a confidence score to help you decide. |
| invalid | Free | The mailbox does not exist or the domain has no MX records. Do not send. |
| unknown | Free | The mail server did not respond or returned an ambiguous result. Retry later. |
| disposable | Free | The email uses a known temporary or disposable provider. Likely not a real user. |
Many email validation services only check syntax and DNS records. Here is what sets GTMData apart from tools like ZeroBounce, NeverBounce, and Kickbox.
Whether you are cleaning a CRM, validating signups in real time, or powering outbound campaigns, GTMData handles it.
Upload your contact list and remove invalid emails in minutes. Reduce bounce rates, protect your sender reputation, and keep your CRM data accurate.
Add email validation to your registration flow. Block disposable emails and catch typos before they enter your database, improving activation rates and reducing fraud.
Verify every email before it enters your outbound sequence. Higher deliverability means more replies, fewer bounces, and a protected domain reputation.
Combine email validation with provider detection to segment leads by their email host. Route Google Workspace users differently from Microsoft 365 users for better personalization.
Need to clean an entire list? Upload a CSV through the dashboard or use the batch API endpoint. GTMData processes bulk validation jobs asynchronously and notifies you when results are ready.
400
Free validations to start
<5ms
Cached lookup speed
5,000+
Disposable domains blocked
GTMData integrates with Clay, Make, Zapier, and any tool that supports HTTP APIs. Use our email validation API alongside the Email Finder API to build complete email enrichment workflows.
Email validation is the process of verifying that an email address is real, active, and capable of receiving messages. It matters because sending emails to invalid addresses increases your bounce rate, damages your sender reputation with ISPs like Google and Microsoft, and wastes resources in your CRM and marketing automation tools. A high bounce rate can lead to your domain being flagged as spam, reducing deliverability for all your email communications.
Syntax checking only confirms that an email address follows the correct format (e.g., user@domain.com). It cannot tell you whether the mailbox actually exists. SMTP verification goes further by connecting to the recipient mail server, performing a handshake, and checking whether the server will accept mail for that specific address. This catches deactivated accounts, typos in the local part, and non-existent mailboxes that pass syntax validation.
A catch-all (or accept-all) domain is configured to accept email sent to any address at that domain, whether the specific mailbox exists or not. This makes traditional SMTP validation unreliable because the server always responds positively. GTMData uses convention matching, SMTP timing analysis, and historical data to assign a confidence score to emails on catch-all domains, helping you decide whether to include them in your outreach.
No. GTMData never sends an email to the address being validated. We perform verification at the SMTP protocol level by initiating a connection and checking the server response, then disconnecting before any message is transmitted. The recipient never knows their address was checked.
Each email validation costs 0.25 credits when the result is valid or catch-all. Invalid, unknown, and disposable results are completely free. You start with 100 free credits (enough for 400 validations), and paid plans begin at $49/month for 2,500 credits. Visit our pricing page for full details.
100 free credits. No credit card required. Full SMTP verification from day one.