Email Verification Waterfall by Signaliz

Built after sending 100 million+ emails across hundreds of clients — many enterprise. This is the verification pipeline behind Signaliz, a SaaS product by Content Marketing Media (CMM). No API keys needed. Just paste your emails and run.

Enterprise partners

Signaliz is an enterprise partner with Clay, Instantly, Octave, and Heyreach.

What does this Actor do?

This Actor verifies whether email addresses are deliverable before you send to them. It uses a multi-provider waterfall approach to maximize accuracy:

1. Primary verification checks every email against a high-throughput provider
2. Catch-all domains (where the primary provider can't give a definitive answer) automatically get routed to a secondary provider for deeper verification

You get a clean email_verified: true/false for every email, ready to load into your outbound tools.

Built for those serious about email validation

This isn't a toy verification tool. It was built from hard-won experience running high-volume outbound at scale — 12M+ emails/month across 20+ active client accounts. Every edge case you'll hit at volume (catch-all domains, disposable addresses) is handled.

Key features

• Waterfall verification — Multi-provider pipeline catches what single tools miss
• Catch-all resolution — Don't lose enterprise leads on catch-all domains
• Disposable email detection — Auto-rejects known disposable/temp email providers
• CSV batch support — Upload thousands of emails at once, all original columns preserved
• Clean output — Export results as JSON, CSV, or Excel

Who is this for?

• Cold email agencies pre-verifying before loading into Instantly, Smartlead, Lemlist
• SDRs and sales teams cleaning prospect lists before outreach
• Growth engineers building verification into automated pipelines
• Data teams maintaining CRM hygiene at scale
• Anyone who wants bounce rates below 2%

Input

Field	Required	Description
emails	No*	List of email addresses to verify
emailsCsv	No*	CSV content with an email column
emailColumn	No	Column name if not "email" (default: email)
batchSize	No	Emails per API call, 1–100 (default: 100)

*At least one of emails or emailsCsv must be provided.

Output

Each verified email is pushed to the Apify dataset:

{
  "success": true,
  "email": "jane@stripe.com",
  "email_verified": true,
  "email_is_catch_all": true,
  "credits_used": 0.5,
  "verification_details": {
    "free": false,
    "role": false,
    "quality": "risky",
    "initial_status": "catch_all",
    "catch_all_result": "deliverable"
  }
}

A summary is saved to the key-value store under OUTPUT:

{
  "total_emails": 500,
  "total_verified": 412,
  "verification_rate": "82.4%",
  "completed_at": "2026-04-05T12:05:00.000Z"
}

Pricing

Pay-per-result through Apify. No external API keys or accounts needed.

API usage

curl -X POST "https://api.apify.com/v2/acts/YOUR_USERNAME~email-verification-waterfall/runs?token=YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "emails": ["john@acme.com", "jane@bigcorp.com"]
  }'

Integrations

Works with Zapier, Make, n8n, and any tool that integrates with Apify Actors. Use it as a pre-verification step before loading into Instantly, Smartlead, Apollo, Lemlist, HeyReach, or any sequencing tool.

About Signaliz

Signaliz is a GTM data quality platform built by Content Marketing Media, a B2B outbound agency sending 12M+ emails/month across 20+ client accounts. Signaliz is an enterprise partner with Clay, Instantly, Octave, and Heyreach.