Features

Email verifier features built for accuracy.

Every feature is designed around one goal: a definitive deliverable or undeliverable for every email on your list.

Core technology

Two engines. Sequenced.

Most verifiers run a single check and give up on catch-all domains. Ours runs two independent verification systems in sequence. Pass 1 handles the obvious cases fast. Pass 2 resolves what Pass 1 marked as unknown.

Pass 01 - Primary

Validates syntax, DNS, MX records, and SMTP mailbox existence. 20 concurrent checks per list. Resolves 70-85% of emails in under a minute.

Pass 02 - Catch-all

Re-verifies catch-all and unknown results from Pass 1 using deep SMTP-level verification with waterfall routing.

Result flow

ok→deliverablePass 01

invalid→undeliverablePass 01

disposable→undeliverablePass 01

catch_all→deliverable / riskyPass 01 + 02

unknown→deliverable / unknownPass 01 + 02

Catch-all resolution

ops@orbital.tech

DNS / MX check

Pass

SMTP mailbox probe

Catch-all

Pass 02 - waterfall

Risky · score 68

Final resultRisky

Accuracy advantage

Resolve the addresses other verifiers give up on.

Catch-all domains accept mail for any address, including ones that don’t exist. Standard SMTP verification can’t tell the difference. Our second pass uses multiple verification vectors to determine whether a specific mailbox actually exists behind a catch-all domain.

15-30%

of B2B lists are catch-all

72%+

resolved to a definitive result

Bulk processing

Drop a CSV. We handle the rest.

Drag in lists up to 50MB and 1 million rows. The email column is auto-detected, duplicates are removed, and we show the exact credit cost before you start.

Auto email column detection - no manual mapping
Client-side preview before commit
Deduplication and normalization
Up to 50MB and 1M rows per file
Live progress polling every 5 seconds
Filtered exports: all / deliverable / undeliverable

Verifying - client_list_q4.csv

Pass 01 - Primary10,247 / 10,247

Pass 02 - Catch-all1,847 / 2,562

Deliverable

6,964

Undeliverable

2,098

Risky

138

Terminal

# Verify a single email
curl https://www.leadlistverifier.com/api/v1/verify \
  -H "Authorization: Bearer llv_..." \
  -d "email=alex@acme.io"

# Response
{
  "email": "alex@acme.io",
  "result": "deliverable",
  "score": 96,
  "engine": "primary",
  "is_role": false
}

Developer API

Verify from your own stack.

A REST API with key-based auth, predictable JSON responses, bulk endpoints, and webhook delivery for async jobs. Drop it into your signup flow, your CRM, or your enrichment pipeline.

Read the API reference

Security & reliability

Your data, handled with care.

Encrypted at rest

CSV uploads stored encrypted with randomized paths.

Atomic credit ops

Every credit deduction runs in a database transaction. No partial charges.

Auto-refunds

Failed jobs return credits to your balance instantly.

Stripe-grade payments

PCI-compliant payment processing. We never see your card details.

Edge-protected auth

JWT sessions verified at the edge. Dashboard guarded by middleware.

Serverless infra

Auto-scaling deploy with reliable background job processing.

See the two-pass difference.

Verify a sample list with 100 free credits. Compare results to your current verifier.

Start with 100 free credits View pricing