Score a B2B Email List Before Cold Outreach
Score B2B emails using syntax, MX, live SMTP mailbox responses, catch-all, disposable, role, provider, and optional domain-health checks.

Most cold-outreach lists need routing, not a binary pass or fail. A valid company domain with a role inbox is different from a malformed address, and both are different from a disposable mailbox. Treating them alike wastes good leads or sends to obvious junk.
Use the Email Verifier & Validator to get a transparent 0–100 score plus the observable inputs behind it. Use the built-in score directly or adapt it to your campaign policy.
Build a simple risk score
Start at 100 and subtract for evidence:
def email_score(row):
if row["status"] == "bad":
return 0
score = row["score"]
if row["role"]:
score -= 10
if row["free"]:
score -= 5
health = row.get("domainHealth") or {}
if not health.get("spf"):
score -= 10
if not health.get("dmarc"):
score -= 10
return max(score, 0)The exact weights should reflect the campaign. A partnership campaign may welcome partnerships@; a named-account sequence should prefer person-level business addresses.
Create operational bands
Scores are useful only when they lead to a decision. A workable policy is:
| Score | Action |
|---|---|
| 80-100 | Eligible for normal sequence |
| 50-79 | Manual review or low-volume test |
| 1-49 | Hold for enrichment |
| 0 | Suppress |
Measure bounce and reply rates by band. After several sends, adjust weights from your own outcomes rather than copying a generic industry model.
Join verification with account context
Email hygiene should not replace lead qualification. Join the result to company size, intent, territory, and source. A high-scoring address at the wrong account is still a bad lead. A role address at a perfect target account may deserve manual research.
Save technical_status, reason, and the raw flags alongside the final score. If the policy changes, you can rescore the list without repeating DNS and SMTP checks.
The result is a smaller, better-routed send list and a scoring process sales operations can inspect line by line.
Frequently asked questions
What score guarantees delivery?
None. SMTP acceptance is strong mailbox evidence, but future delivery also depends on mailbox state, sender reputation, authentication, and message content.
Are role addresses always bad leads?
No. They are usually weaker for person-level outreach, but can be appropriate for procurement, press, partnerships, or customer support workflows.