Understanding Email Deliverability Scores

Email deliverability scores provide a numerical assessment of whether an email address can successfully receive messages. In this guide, we'll explain how these scores work and how to use them effectively.

What is a Deliverability Score?

A deliverability score typically ranges from 0-100 and indicates the likelihood that an email will reach the recipient's inbox. Higher scores mean better deliverability.

Score ranges:

90-100: Excellent - High confidence delivery

70-89: Good - Likely to deliver with minor risks

50-69: Fair - Moderate risk, proceed with caution

0-49: Poor - High risk of bounce or spam folder

Factors That Affect Scores

Multiple factors contribute to deliverability scoring:

1. Domain Reputation

The sending domain's historical performance:

Previous bounce rates

Spam complaints

Blacklist status

Authentication setup (SPF, DKIM, DMARC)

2. Mailbox Status

The recipient email's characteristics:

Active vs inactive mailbox

Recent engagement patterns

Catch-all configuration

Temporary vs permanent address

3. Email Infrastructure

Technical validation results:

Valid MX records

Mail server responsiveness

SPF/DKIM alignment

SSL/TLS support

4. Risk Indicators

Patterns that suggest problems:

Disposable email service

Role-based address (info@, admin@)

Syntax irregularities

Known spam trap

How PilotVerify Calculates Scores

Our scoring algorithm combines multiple validation checks:

Score = (Syntax × 20) + (MX × 25) + (SMTP × 30) + (Reputation × 25)

Each component is weighted based on reliability:

1. Syntax check (20%): Basic format validation

2. MX verification (25%): Domain can receive email

3. SMTP verification (30%): Mailbox actually exists

4. Reputation (25%): Historical patterns and risks

The final score adjusts based on negative indicators like disposable domains or catch-all detection.

Using Scores in Practice

Marketing Campaigns

Set minimum thresholds based on campaign importance:

High-value: Score ≥ 80 (product launches, announcements)

Regular: Score ≥ 60 (newsletters, promotions)

Re-engagement: Score ≥ 40 (win-back campaigns)

User Registration

Different thresholds for different flows:

if (score >= 80) {
  // Allow registration, high confidence
  registerUser(email)
} else if (score >= 50) {
  // Allow with email verification required
  registerWithVerification(email)
} else {
  // Reject or suggest correction
  showError("Please check your email address")
}

Data Cleanup

Segment your database by deliverability:

90-100: Prime contacts - maximum engagement

70-89: Good contacts - regular campaigns

50-69: Risky contacts - re-validation needed

0-49: Remove or suppress

Improving Your Deliverability

Actions to boost your overall deliverability:

1. Authenticate Your Domain

Implement email authentication:

SPF (Sender Policy Framework)

DKIM (DomainKeys Identified Mail)

DMARC (Domain-based Message Authentication)

2. Maintain List Hygiene

Regular maintenance practices:

Remove hard bounces immediately

Suppress soft bounces after 3 attempts

Re-validate inactive subscribers quarterly

Remove unengaged contacts after 6 months

3. Monitor Engagement

Track recipient interactions:

Open rates

Click-through rates

Reply rates

Unsubscribe rates

Low engagement signals to mailbox providers that your emails aren't wanted.

4. Use Double Opt-in

Require email confirmation for new subscribers:

Validates the address is real

Ensures recipient wants emails

Reduces spam complaints

Improves long-term deliverability

Common Misconceptions

Myth: A valid email always delivers

Reality: Validation confirms format and mailbox existence, but spam filters, full inboxes, and blocks can still prevent delivery.

Myth: Low scores mean bad data

Reality: Some legitimate addresses score lower (new domains, strict servers). Use scores as guidance, not absolute rules.

Myth: One-time validation is enough

Reality: Email validity changes over time. Re-validate important contacts regularly.

API Response Example

Here's what a PilotVerify API response looks like:

{
  "email": "user@example.com",
  "status": "VALID",
  "deliverability_score": 87,
  "checks": {
    "syntax": true,
    "mx_records": true,
    "smtp_valid": true,
    "is_disposable": false,
    "is_role_based": false,
    "is_free_email": false
  },
  "recommendation": "ACCEPT",
  "risk_level": "LOW"
}

Use the deliverability_score and recommendation fields to make decisions.

Conclusion

Email deliverability scores provide valuable insights for managing your contact database and email campaigns. By understanding how scores work and applying appropriate thresholds, you can maximize deliverability while maintaining list quality.

Remember: scores are guidance, not guarantees. Combine deliverability scoring with engagement metrics and authentication best practices for optimal results.

[Start validating emails](/pricing) with PilotVerify's deliverability scoring today.