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Every email analysis returns deliverability signals that help you decide whether it is safe to send to an address. The webhook payload includes two fields for this purpose: send_recommendation and deliverability.risk_score. This guide explains what each field means and how to use them.

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Two Fields, One Decision

The deliverability section of the webhook payload contains: 
{
  "deliverability": {
    "risk_score": -1,
    "send_recommendation": "send"
  }
}
  • send_recommendation is the primary decisioning field. It combines deliverability with other risk factors (such as disposable or impersonation domains) into a single, actionable recommendation.
  • deliverability.risk_score is a narrower signal based on SMTP verification. Use it when you need more granular control over your send logic.
For most use cases, send_recommendation is all you need.

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send_recommendation

ValueMeaningWhen it triggers
sendSafe to sendThe email is confirmed deliverable or has no adverse deliverability signal
send_with_cautionSome bounce riskThe email has uncertain deliverability (unknown SMTP status, mailbox full, or risky status), or the overall risk_score is very high
do_not_sendDo not sendThe email is confirmed invalid, is a no-reply address, or the domain is disposable, invalid, or an impersonation
send_recommendation accounts for more than just SMTP results. An email on a disposable domain will return do_not_send even if the mailbox technically exists, because disposable addresses are short-lived and poor targets for outreach.

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deliverability.risk_score

The deliverability.risk_score ranges from -1 (deliverable) to 1 (not deliverable). The table below shows roughly where scores land and what they indicate:
Score rangeInterpretation
Around -1Confirmed deliverable — SMTP verification succeeded
Around 0Unable to verify — the mail server did not provide a definitive answer (e.g., catch-all domains, rate-limited servers)
Around 0.5Uncertain — SMTP status is unknown or the mailbox is full
Around 0.75Likely undeliverable — SMTP verification returned a risky status
Around 1Not deliverable — the email is confirmed invalid or is a no-reply address
A score around 0 means Verisoul was unable to verify the address — it does not mean the email is unsafe. Many emails that cannot be SMTP-verified (for example, those on catch-all domains) deliver fine in practice.

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Which Should I Use?

Use send_recommendation as your only filter:
  • send — safe to email
  • send_with_caution — you can still send, but expect some bounce risk
  • do_not_send — skip this address
This is the recommended approach for most customers.
Start with send_recommendation, then layer on deliverability.risk_score for tighter control:
  1. Exclude anything with send_recommendation = "do_not_send"
  2. Additionally exclude emails where deliverability.risk_score > 0 to limit sending to addresses that are either confirmed deliverable or simply unverifiable
Keep in mind that filtering on risk_score > 0 will exclude emails where SMTP verification was inconclusive. Many of those addresses are perfectly deliverable — this approach trades some reach for lower bounce rates.
Use the top-level decision and risk_score fields instead. Deliverability is already factored into the overall risk assessment, so you do not need to check deliverability separately.

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How Deliverability Affects the Overall Score

The deliverability.risk_score is one of several sub-scores that feed into the overall risk_score returned in the webhook. An undeliverable email will push the overall score toward risk, while a confirmed-deliverable email contributes a trust signal. The overall risk_score also incorporates breach history, email age, domain reputation, username patterns, and (when enabled) identity intelligence. See the Webhook Payload Reference for the full list of fields.