mailboxlayer

Overview

Mailboxlayer (an APILayer product) validates email addresses — syntax, MX/SMTP checks, disposable detection, and risk scores. Auth is a free API key — like other APILayer APIs, invalid keys return HTTP 200 with "success": false (verified).

Quick Start

Validate an email (replace YOUR_KEY):

curl "http://apilayer.net/api/check?access_key=YOUR_KEY&[email protected]"

{
  "success": true,
  "email": "[email protected]",
  "format_valid": true,
  "mx_found": true,
  "smtp_check": true,
  "disposable": false,
  "score": 0.9
}

Authentication

• Register at mailboxlayer.com → free API key (emailed).
• Send it as the access_key query parameter.
• Invalid keys return 200 + "success": false (verified) — check the JSON.

Rate Limits & Notes

• Free tier: 250 requests/month; paid plans scale.
• The API is served over http (https is paid on some tiers) — use https when available.
• Fields: format_valid, mx_found, smtp_check, disposable, score (0-1 risk).
• SMTP checks are the most expensive operation — they can be slow or rate-limited.

FAQ

Is Mailboxlayer free? Free tier: 250 requests/month; more is paid.

Why 200 with success:false? APILayer convention — check the success field in the response body.

What does score mean? A 0-1 deliverability/risk score for the address.