Terminology & Status Codes

Understanding ClearBounce verification results.

Email Status

The status field indicates the overall verification result:

deliverable

The email address is confirmed to exist and can receive mail.

{
  "status": "deliverable",
  "subStatus": "accepted_email",
  "reason": "accepted_email",
  "score": 100,
  "isDeliverable": true,
  "toxicity": 0
}

Recommended action: Safe to send emails.

---

undeliverable

The email address does not exist or cannot receive mail.

{
  "status": "undeliverable",
  "subStatus": "rejected_email",
  "reason": "rejected_email",
  "score": 0,
  "isDeliverable": false,
  "toxicity": 0
}

Recommended action: Remove from your list. Do not send.

---

risky

The email might be deliverable but has risk factors (includes catch-all domains).

{
  "status": "risky",
  "subStatus": "low_quality",
  "reason": "low_quality",
  "score": 45,
  "isDeliverable": false,
  "toxicity": 2
}

Recommended action: Use with caution based on your risk tolerance.

---

unknown

Could not determine validity (server timeout, blocked verification, etc.)

{
  "status": "unknown",
  "subStatus": "unavailable_smtp",
  "reason": "unavailable_smtp",
  "score": 50,
  "isDeliverable": false,
  "toxicity": 0
}

Recommended action: Consider retrying or use your own judgment.

---

Sub-Status Codes

More specific reasons for the status:

Sub-Status	Description	Status
accepted_email	Mailbox confirmed to exist	deliverable
invalid_syntax	Email format is invalid	undeliverable
invalid_domain	Domain has no mail server	undeliverable
rejected_email	Mailbox does not exist or SMTP rejected	undeliverable
low_quality	Disposable, role-based, or possible typo email	risky
low_deliverability	Catch-all domain or may have delivery issues	risky
unavailable_smtp	Mail server timed out or connection failed	unknown
unsupported	Greylisted or unsupported mail server	unknown

Deliverability Score

A 0-100 score indicating confidence in deliverability:

Score Range	Meaning	Recommendation
90-100	Excellent	Safe to send
70-89	Good	Generally safe
50-69	Moderate	Proceed with caution
30-49	Poor	Consider removing
0-29	Very Poor	Do not send

Check Results

Syntax Check

{
  "checks": {
    "syntax": true  // Valid email format
  }
}

MX Records Check

{
  "checks": {
    "mxRecords": true  // Domain can receive email
  }
}

SMTP Validation

{
  "checks": {
    "smtpValid": true   // Mailbox exists
    // null = could not verify
    // false = mailbox doesn't exist
  }
}

Disposable Detection

{
  "checks": {
    "isDisposable": true  // Temporary email service
  }
}

Common disposable providers: mailinator.com, guerrillamail.com, tempmail.com, etc.

Role-Based Detection

{
  "checks": {
    "isRoleBased": true  // Generic/group address
  }
}

Examples: info@, support@, admin@, sales@, contact@

Free Provider Detection

{
  "checks": {
    "isFreeProvider": true  // Free email service
  }
}

Examples: gmail.com, yahoo.com, outlook.com, hotmail.com

Catch-All Detection

{
  "checks": {
    "isCatchAll": true  // Domain accepts all addresses
  }
}

Catch-all domains accept emails to any address, making individual mailbox verification impossible. Catch-all emails are classified as risky with reason low_deliverability and a score of 90.

Account Status

{
  "checks": {
    "account": {
      "fullMailbox": true,   // Mailbox storage exceeded
      "disabled": false      // Account deactivated
    }
  }
}

Meta Information

Provider

{
  "meta": {
    "provider": "google.com"  // Email service provider
  }
}

Extracted from MX records. Examples: google.com, microsoft.com, yahoo.com

DNS Type

{
  "meta": {
    "dnsType": "MX"  // Record type used
  }
}

• MX: Mail Exchange record (preferred)
• A: Address record fallback (less reliable)

Typo Suggestion

{
  "checks": {
    "hasTypo": {
      "original": "gmial.com",
      "suggested": "gmail.com",
      "confidence": 0.95
    }
  }
}

Toxicity Score

A 0-5 scale indicating the toxicity level of the email address:

Score	Meaning
0	No toxicity detected
1	Very low toxicity
2	Low toxicity
3	Moderate toxicity
4	High toxicity
5	Very high toxicity

Reason Field

The reason field provides the same value as subStatus, offering a human-friendly explanation for the verification result. See the Sub-Status Codes table above.

Risk Factors

Array of human-readable reasons for risky classifications:

{
  "riskFactors": [
    "disposable_domain",
    "high_risk_tld",
    "recently_created_domain"
  ]
}

Common risk factors:

• disposable_domain: Temporary email service
• role_based_address: Generic address like info@
• catch_all_domain: Domain accepts all emails
• free_email_provider: Gmail, Yahoo, etc.
• suspicious_pattern: Unusual email format