01
Deliverable
Accept the address
The mailbox check completed and the address can continue through your normal signup, checkout, or lead flow.
State: "Deliverable"
Built for production signup and lead workflows
Verify emails without turning temporary replies into false negatives.
Check mailbox deliverability in real time, detect risky email patterns, retry greylisted results safely, and get more useful answers for supported catch-all business domains.
Free verification credits included with new accounts. One request uses one credit.
No email sent
Real-time response
Retry-aware results
Any HTTPS stack
First request
curl "https://api.ValidEmail.net/?email=user@example.com&token=YOUR_API_KEY"DeliverableContinue or apply your score-based risk policy.
State: DeliverableUnknownWait, then query again using the retry hint.
RetryAfterSecondsNot DeliverableBlock, suppress, or request another address.
Score 0A safer integration contract
Three outcomes. One clear decision path.
A temporary response is not the same as an invalid mailbox. Route by State, then use RetryAfterSeconds whenever the answer is still being resolved.
02
Unknown
Defer the decision
The mail server gave a temporary answer. Keep the user moving with a softer path, then retry after the returned interval.
Reason: "PENDING" or "GREYLISTED"
03
Not Deliverable
Stop or suppress
The domain or mailbox produced a permanent negative result. Ask for a correction or keep it out of sending workflows.
State: "Not Deliverable"
Recommended routing
Do not block every
Do not block every IsValid: false response.
An Unknown result is intentionally non-final. Checking the state prevents temporary SMTP behavior from becoming a false rejection in your product.
if (result.State === "Deliverable") allow();
else if (result.State === "Unknown" && result.RetryAfterSeconds) retryLater();
else blockOrReview();Why the answer is more useful
Designed to preserve uncertainty instead of hiding it.
ValidEmail combines familiar deliverability signals with provider-aware checks and a real temporary-result lifecycle.
Temporary-aware
Transport failures and inconclusive SMTP responses stay Unknown. They are not cached as permanent negatives.
Greylist-aware
Delayed re-verification reuses a stable SMTP identity, while the API tells your integration when to query again.
Catch-all aware
Supported Google Workspace and Microsoft 365 domains can receive a mailbox-level existence check beyond the domain's accept-all behavior.
Catch-all business email
Go beyond “this domain accepts everything.”
Catch-all SMTP behavior can hide whether a specific mailbox exists. For supported Google Workspace and Microsoft 365 domains, ValidEmail asks for a mailbox-level answer and uses it only when it is definitive.
Google Workspace Microsoft 365
Catch-all detectedThe domain accepts a made-up recipient.
Mailbox existsReturn the confirmed mailbox verdict without a catch-all score penalty.
Mailbox does not existReturn a definitive not-deliverable result.
No definitive answerKeep the honest, conservative catch-all result.
Quick start
From API key to first decision in a few lines.
The public endpoint is versionless. Send an HTTPS request from any language, then branch on the response state.
JavaScript
const params = new URLSearchParams({
email: "user@example.com",
token: process.env.VALIDEMAIL_API_KEY
});
const response = await fetch(`https://api.ValidEmail.net/?${params}`);
if (response.status === 429) throw new Error("Rate limited");
const result = await response.json();
if (result.State === "Deliverable") return allow();
if (result.State === "Unknown" && result.RetryAfterSeconds) {
return retryAfter(result.RetryAfterSeconds);
}
return blockOrReview(result.Reason);Straightforward pricing
Buy the checks you need. Keep the credits you do not use.
New accounts include free verification credits. Purchased credits do not expire and work across API and bulk verification.
Developer FAQ
Know what to ship before you integrate.
Which endpoint should I use?
Use https://api.ValidEmail.net/ with email and token query parameters. The root endpoint runs the current verification system.
What is the difference between PENDING and GREYLISTED?
GREYLISTED means the mail server explicitly delayed the mailbox check. PENDING covers other temporary or still-running outcomes. Both remain Unknown and may include a retry hint.
Should I block an Unknown result?
Not as a permanent invalid address. Use a softer product path and retry after RetryAfterSeconds when it is present.
How does catch-all verification work?
ValidEmail detects accept-all behavior first. Supported Google Workspace and Microsoft 365 domains may then receive a mailbox-level check. If that check is inconclusive, the API keeps a conservative catch-all result.
Which fields are returned?
IsValid, Score, Email, State, Reason, Domain, Free, Role, Disposable, AcceptAll, Tag, MXRecord, RetryAfterSeconds, and EmailAdditionalInfo.
Does verification send an email?
No. ValidEmail checks deliverability signals without sending a message to the address.
How do credits and rate limits work?
One request uses one credit. Rate limits are applied per API key, and limited requests return HTTP 429. Contact support for workload-specific limits.
Where can I get implementation help?
Use the API guide, response guide, or contact support.
Start with free verification credits
Ship a better email decision today.
Get your API key, make one request, and handle deliverable, temporary, and not-deliverable results correctly from the start.
Get Your API Key