Verify Email API · Built for AI Agents

Email Verification API for AI Agents

One API call returns format validation, MX lookup, SMTP mailbox probe, and catch-all detection — all as structured JSON your agent can act on immediately. No signup required. No dashboard. Pay per verification.

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Response time

Median < 1.5 s — fast enough for synchronous agent decisions

No signup

Buy credits once, call the API. No account, no dashboard, no keys to manage.

Coverage

Format · MX · SMTP · Catch-all — four checks, one JSON response

Verify Email API

One request. Instant JSON decision.

No signup

curl

curl -X POST https://verifymail.nanocorp.app/api/verify \
  -H "Authorization: Bearer vm_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"email": "prospect@company.com"}'

JSON response

{
  "email": "prospect@company.com",
  "status": "valid",
  "reason": "Mailbox confirmed via SMTP",
  "catch_all": false,
  "confidence": "high",
  "checks": {
    "format": true,
    "mx": true,
    "smtp": true,
    "catch_all": false
  }
}

POST /api/verify

status: valid | invalid | risky

catch_all detection

confidence: high | medium | low

How the verify email API works

Four verification layers. One JSON response.

Each call runs format validation, DNS MX lookup, SMTP mailbox probing, and catch-all detection. The result maps directly to agent routing logic without intermediate transformation.

Format validation

Reject malformed addresses immediately

Before any network call, the API normalizes and validates the address structure. Bad syntax is flagged without burning credits on DNS or SMTP work.

MX record lookup

Confirm the domain can receive mail

VerifyMail checks that the domain publishes valid MX records. A missing or broken MX means no email can land there, regardless of what the address looks like.

SMTP mailbox probe

Test whether the specific mailbox exists

A lightweight SMTP handshake confirms whether the exact mailbox is live. No email body is sent. This is what separates VerifyMail from domain-only checkers.

Catch-all detection

Flag risky domains that accept everything

Some domains are configured to accept mail to any address — even fake ones. VerifyMail detects this and returns catch_all: true so your agent can downgrade confidence and route accordingly.

API reference

Full request and response spec.

The verify email API accepts a single email address and returns a structured JSON object your agent can use immediately for routing, filtering, or logging.

Endpoint

POST /api/verify

Auth

Authorization: Bearer vm_live_your_api_key

Content-Type

application/json

Body

{ "email": "user@example.com" }

Example request (curl)

curl -X POST https://verifymail.nanocorp.app/api/verify \
  -H "Authorization: Bearer vm_live_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"email": "prospect@company.com"}'

JSON response

{
  "email": "prospect@company.com",
  "status": "valid",
  "reason": "Mailbox confirmed via SMTP",
  "catch_all": false,
  "confidence": "high",
  "checks": {
    "format": true,
    "mx": true,
    "smtp": true,
    "catch_all": false
  }
}

Response field reference

status

"valid" | "invalid" | "risky"

Primary agent routing signal.

confidence

"high" | "medium" | "low"

Based on depth of verification path.

catch_all

boolean

true means the domain accepts mail to any address.

reason

string

Human-readable explanation for logs or debugging.

checks.format

boolean

Address passed format normalization.

checks.mx

boolean

Domain publishes valid MX records.

checks.smtp

boolean

Mailbox responded to SMTP probe.

Why it's built for autonomous agents

Traditional tools were designed for humans with dashboards.

VerifyMail is shaped for the call-and-decide pattern that agents need: one HTTP call inside the agent loop, structured JSON out, no human in the path.

No signup flow in the path

Traditional email verification tools assume a human will log in, create a project, upload a CSV, and wait for a batch report. Agents need to call an endpoint and get a decision in the same execution context.

Per-use credits, not monthly seats

Agent workloads are bursty. A single outreach run might verify 200 addresses; the next day might be zero. Monthly subscription models punish variable usage. VerifyMail credits are consumed only when the API is called.

Fast enough to stay synchronous

Median response time under 1.5 seconds. Fast enough that your agent can verify before it sends, enriches, or stores — no need to offload to a separate async batch job.

JSON that maps to agent decisions

The response is shaped for branching: status is "valid", "invalid", or "risky". Confidence is "high", "medium", or "low". Catch-all is a boolean. Your agent can route on these values without parsing free-text.

Use cases

Verify email API for every agent workload.

From single-address probes to bulk email verification API calls, VerifyMail covers the patterns agents actually use.

AI outreach agents

Verify each email address before queuing a send sequence. Catch dead mailboxes before they burn sender reputation and tokens.

Lead scraping pipelines

Validate scraped contacts inline so invalid records never reach your CRM, enrichment layer, or messaging queue.

Bulk email verification API

Call /api/verify in a loop or batched worker for large lists. Credits are consumed per call — no upload UI, no waiting for a batch report.

Catch-all detection at scale

Route addresses with catch_all: true to a lower-confidence segment automatically. Don't let entire catch-all domains inflate your valid list.

Pricing — no signup, per-use credits

Pay for verifications. Not for a seat.

Credits are consumed per API call. No monthly subscription. No minimum spend beyond your initial pack. Start at $5 for 100 checks.

Add email verification to your agent pipeline today.

100 verifications for $5. No signup. No dashboard. An API key lands in your inbox after checkout — start calling the API in minutes.

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