Email Validation Overview

Cleanmails includes a high-performance email validation engine that checks addresses through multiple layers — from instant syntax checks to deep SMTP handshakes. It supports single verification via API and bulk processing of 100k+ lists.

Validation Levels

Level 1 — Fast Analysis (Near-Instant)

Performs all checks that don't require network connections:

• Syntax validation — RFC-compliant regex check
• MX record lookup — Verifies the domain has mail servers
• Disposable detection — Checks against 126,000+ known disposable domains (auto-updated daily)
• Role-based detection — Identifies addresses like info@, admin@, support@
• Free provider detection — Flags Gmail, Yahoo, Outlook, etc.
• Domain suggestion — Suggests corrections for typos (e.g., gmial.com → gmail.com)

Level 2 — Deep SMTP Handshake

Performs a real SMTP conversation with the recipient's mail server:

• Mailbox existence check — Sends RCPT TO command to verify the address exists
• Catch-all detection — Tests with random addresses to detect accept-all domains
• Full inbox detection — Identifies mailboxes that are over quota
• Greylisting detection — Handles temporary rejections
• API-based verification — Uses specialized methods for Google, Yahoo, and Outlook

Verification Result

Every verification returns a structured result:

{
  "email": "john@example.com",
  "reachable": "yes",
  "syntax": {
    "username": "john",
    "domain": "example.com",
    "valid": true
  },
  "smtp": {
    "host_exists": true,
    "full_inbox": false,
    "catch_all": false,
    "deliverable": true,
    "disabled": false
  },
  "gravatar": {
    "has_gravatar": true,
    "gravatar_url": "https://www.gravatar.com/avatar/..."
  },
  "suggestion": "",
  "disposable": false,
  "role_account": false,
  "free": false,
  "has_mx_records": true
}

Reachable Values

Single Email Verification

curl -X POST http://YOUR_SERVER/v1/verify \
  -H "Content-Type: application/json" \
  -H "Cookie: auth_token=YOUR_SESSION" \
  -d '{"email": "john@example.com", "level": 2}'

Bulk Verification

Submit up to 100,000 emails in a single request:

curl -X POST http://YOUR_SERVER/v1/bulk \
  -H "Content-Type: application/json" \
  -H "Cookie: auth_token=YOUR_SESSION" \
  -d '{
    "emails": ["user1@example.com", "user2@test.com", "..."],
    "level": 2,
    "concurrency": 100,
    "store_results": true
  }'

Returns a job ID that you can poll for status:

# Check job status
curl http://YOUR_SERVER/v1/bulk/JOB_ID

# Get results (paginated)
curl "http://YOUR_SERVER/v1/bulk/JOB_ID/results?offset=0&limit=1000"

# Download as CSV
curl http://YOUR_SERVER/v1/bulk/JOB_ID/download

Provider-Specific Verification

Cleanmails uses specialized API-based methods for major providers that block traditional SMTP checks:

Performance