Email Validation API

Email / API Key Intermediate HTTPS CORS
Varies by plan (check documentation)

Overview

Abstract API Email Validation checks whether an email address is deliverable, properly formatted, and not from a disposable or spam-trap domain. It performs DNS MX record checks, SMTP verification, and syntax analysis to give a multi-signal verdict without actually sending an email. An API key from abstractapi.com is required; a free tier with limited monthly checks is available.

💡

Beginner Tip

Email validation APIs are useful when building sign-up forms — they catch typos and fake addresses before they enter your database. You need an API key from abstractapi.com; the free tier is generous enough for small projects and testing.

Available Data

email delivery status
message ID
bounce/complaint data
open/click tracking

Example Response

JSON Response
{
  "message_id": "msg_abc123def456",
  "status": "delivered",
  "to": "[email protected]",
  "subject": "Welcome!",
  "timestamp": "2025-01-15T10:30:00Z"
}

Field Reference

email The email address that was submitted for validation
deliverability Overall deliverability verdict: DELIVERABLE, UNDELIVERABLE, or RISKY
is_valid_format Contains a boolean value field indicating whether the email passes RFC 5321 syntax rules
is_mx_found Contains a boolean value field indicating whether a valid MX record was found for the email domain
is_disposable_email Contains a boolean value field flagging known temporary or throwaway email providers
quality_score A 0.0–1.0 score summarizing overall email quality and deliverability likelihood

Implementation Example

const url = "https://www.abstractapi.com/email-verification-validation-api";
// Replace headers or query params with the values required by this API.
const response = await fetch(url, {
  headers: {
  "X-API-Key": "YOUR_API_KEY"
  }
});
if (!response.ok) throw new Error(`Request failed: ${response.status}`);
const data = await response.json();
console.log(data);

What Can You Build?

Note: These code examples are AI-generated and unverified. Always refer to the official API documentation for accurate usage.

Common Errors & Troubleshooting

401 Unauthorized The api_key query parameter is missing or the key has been regenerated since you last copied it
Log into abstractapi.com, copy the current key from the Email Validation dashboard, and include it as ?api_key=YOUR_KEY in every request
"deliverability": "UNDELIVERABLE" for a valid address The email domain may have strict SMTP policies that reject probe connections used for verification
Treat UNDELIVERABLE as a soft signal — combine it with is_valid_format and is_mx_found before rejecting an address outright
Slow response (3+ seconds) SMTP verification requires a live connection to the recipient mail server, which can be slow or timeout-prone
Set an HTTP timeout of at least 10 seconds in your client; cache results per email address to avoid repeated lookups

Matrix Score Breakdown

🌐 Reachability 30/30
⚡ Speed 20/20
🔒 Security 15/15
🛠 Developer XP 17/20
✓ Reliability 10/15

Partially tested on Apr 5, 2026

Technical Specifications

Auth API Key
HTTPS REQUIRED
CORS YES
Category Email
Difficulty Intermediate
Verified: 2026-04-07

Alternatives to Email Validation

Technical alternatives for different use cases.

Specialized in detecting disposable email addresses

Better For

Blocking temporary/disposable email signups

Trade-off

Full email deliverability checking

Email validation with SMTP check and catch-all detection

Better For

Deep validation with SMTP verification

Trade-off

Free tier availability

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