What are catch-all email addresses?

Catch-all (or accept-all) email domains are configured to accept ALL emails sent to that domain, regardless of whether a specific mailbox exists. While this ensures no email is lost, it makes it impossible to verify if individual addresses like john@company.com actually exist using traditional SMTP methods. The server always responds with '250 OK' — even for addresses that don't exist.

Why are catch-all emails risky?

Catch-all emails are risky because: (1) They may accept emails initially but bounce later (delayed bounces), (2) They often contain spam traps that blacklist senders, (3) Traditional validators can't verify them, leaving you with 'unknown' status, and (4) Sending to invalid catch-all addresses damages your sender reputation and deliverability across ALL your campaigns, not just the one with bounces.

How does LeadMagic verify catch-all emails?

We use proprietary algorithms that go beyond traditional SMTP verification. Our system verifies individual mailboxes within catch-all domains by analyzing multiple signals and patterns, even when security gateways like Proofpoint and Mimecast block standard verification methods. The result is definitive valid/invalid status — not 'unknown.'

How do you handle Proofpoint and Mimecast?

Secure Email Gateways (SEGs) like Proofpoint, Mimecast, and Barracuda intercept and filter emails before they reach mail servers, blocking traditional SMTP verification attempts. Our advanced verification methods work around these security layers to provide accurate validation results without triggering security protocols.

What results will I get?

You'll receive definitive valid/invalid status for each catch-all email address. Unlike traditional validators that return 'unknown' or 'risky' for catch-all domains, LeadMagic provides actionable results so you can confidently include valid addresses in your campaigns or exclude invalid ones.

How is pricing structured?

We use pay-per-result pricing — you only pay for conclusive validation results. If we can't resolve a catch-all email to a definitive valid/invalid status, you're not charged. This means every credit you spend gives you actionable data.

Can I use catch-all validation with Clay or n8n?

Yes. LeadMagic's catch-all validation is available through our REST API, which integrates natively with Clay, n8n, Zapier, and other automation platforms. You can add catch-all validation as a step in your existing enrichment waterfall to resolve any 'unknown' results from your primary verification.

How many enterprise domains are catch-all?

Over 40% of enterprise domains use catch-all configurations or are protected by security gateways. This includes most Fortune 500 companies, Microsoft-hosted domains, and organizations using enterprise email security like Proofpoint, Mimecast, or Barracuda. If you're doing enterprise outbound, catch-all verification isn't optional — it's essential.

What's the difference between catch-all detection and catch-all resolution?

Most email verifiers do catch-all detection — they identify that a domain is catch-all and flag the email as 'unknown' or 'risky.' That's where they stop. LeadMagic does catch-all resolution — we go further and determine whether the specific mailbox within that catch-all domain actually exists and is deliverable. Detection tells you it's risky. Resolution tells you if it's safe to send.

Is catch-all verification different from standard email verification?

Yes. Standard email verification uses SMTP handshakes to check if a mailbox exists — this works on ~60% of domains. Catch-all verification requires specialized techniques because the SMTP server always returns a positive response, making standard methods useless. LeadMagic's standard email verification handles both normal and catch-all domains in one API call, routing catch-all addresses through our specialized algorithms automatically.

Catch-All Validation

Catch-All Email Verification — Resolve 'Unknown' to Valid or Invalid

Other verifiers give up on catch-all domains and flag them as 'unknown.' LeadMagic resolves individual mailboxes within accept-all domains — even behind Proofpoint and Mimecast — with near-zero bounce rates.

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THE PROBLEM

Catch-all emails are killing your campaigns

40%+ of enterprise domains use catch-all configurations. Traditional validators can't verify them — they flag the email as "unknown" and move on. You're forced to skip your highest-value prospects or risk your sender reputation.

15-30%

Delayed Bounce Rates

Catch-all domains accept emails initially, then bounce hours or days later. These delayed bounces destroy your sender reputation and tank deliverability across all your campaigns.

40%+

Enterprise Domains Are Catch-All

Most Fortune 500 companies and enterprise organizations use catch-all or security-gateway-protected domains. Traditional validators mark these as 'unknown' — meaning you lose access to your highest-value prospects.

100%

Security Gateways Block SMTP

Proofpoint, Mimecast, Barracuda, and other SEGs intercept verification attempts. Every other verifier gives up on these domains. Your best prospects are behind these walls.

~0%

Bounce rate on resolved emails

100%

SEG compatibility

<300ms

Response time

Pay-per-result

Only pay for answers

SIMPLE PROCESS

How Catch-All Validation works

Submit catch-all emails

Send risky or catch-all email addresses via API or CSV upload. Works with addresses that other validators mark as 'unknown' or 'accept-all'.

Advanced verification

Our system bypasses security gateways and uses proprietary algorithms to verify individual mailboxes within catch-all domains.

Get verified results

Receive definitive valid/invalid status for each email. Only pay for conclusive results that unlock your risky leads.

Features

Advanced verification for risky emails

Break through security barriers and unlock prospects that other validators can't verify.

Security Gateway Bypass

Works seamlessly with Proofpoint, Mimecast, Barracuda, and other Secure Email Gateways (SEGs) that block traditional SMTP verification.

Individual Mailbox Verification

Proprietary algorithms verify specific email addresses within catch-all domains, not just the domain itself. Get definitive valid/invalid per mailbox.

Spam Trap Detection

Identify honeypots and spam traps hidden within catch-all domains before they blacklist your sender reputation.

Real-time API

Get validation results in under 300ms. Same fast API experience as all LeadMagic products with instant integration via REST API, Clay, or n8n.

Near-Zero Bounce Rates

When we resolve a catch-all email to 'valid,' it delivers. Reduce bounce rates to almost zero and protect your sender reputation.

Unlock Risky Leads

Convert 'unknown' and 'risky' email statuses into actionable valid/invalid results. Reach prospects that every other verifier marks as unverifiable.

Leadmagic is hands down the most reliable email finder and validator I've used, and i've used and tested a lot of them. It doesn't inflate results with fake or low-quality emails just to give you a dopamine hit... everything it returns is legit and usable. A lot of tools quietly burn your budget with bad data, but Leadmagic is transparent and trustworthy. When you're paying for emails, that matters. Because the data actually works, I've made real money using it, and I trust it not to waste my time or steal from my pocket.

Aviv Joseph Glazer

Co-founder, PandaMatch

Detection vs Resolution

Why "catch-all detected" isn't enough

Every email verifier can detect that a domain is catch-all. They see the server accepts all addresses, flag it as "unknown" or "risky," and move on. That's detection — and it's useless for making decisions.

Resolution is what matters. LeadMagic's catch-all validation goes beyond detection to determine whether a specific mailbox within a catch-all domain actually exists and will accept delivery. The difference between "this domain is catch-all" and "john@enterprise.com is a valid mailbox" is the difference between skipping a prospect and closing a deal.

Our proprietary algorithms analyze multiple signals beyond SMTP — patterns, infrastructure fingerprints, historical data, and real delivery outcomes. This works even on domains protected by Proofpoint, Mimecast, and Barracuda, which block traditional SMTP verification entirely.

Catch-All Detection vs Resolution

Detection Only

Result: "unknown"
Skip or send blind
15-30% delayed bounces
No decision value

Resolution (LeadMagic)

Result: valid or invalid
Send with confidence
~0% bounce rate
Actionable for every record

Comparison

How verifiers handle catch-all domains

Every other email verifier stops at detection. LeadMagic resolves.

Verifier	Catch-All Handling	Bounce Rate	Method
LeadMagic	Resolves to valid/invalid	~0%	Proprietary multi-signal algorithms
ZeroBounce	Flags as 'unknown'	15-30% if you send	SMTP only — gives up on catch-all
NeverBounce	Flags as 'unknown'	15-30% if you send	SMTP only — gives up on catch-all
Kickbox	Flags as 'unknown'	15-30% if you send	SMTP only — gives up on catch-all
Bouncer	Limited resolution	5-15%	Basic heuristics
MillionVerifier	Flags as 'risky'	15-30% if you send	SMTP only — gives up on catch-all

I compared LeadMagic to other email finders, and the results made it obvious: LeadMagic had the best data and the best prices. It was a no-brainer to go for an annual deal. The data quality, fair pricing, outstanding support, rapid development, and numerous features made it clear that it was the best option.

Andre Domanski

Founder, Get Sales Meetings

Who needs catch-all verification?

If your outbound targets enterprise companies, you need catch-all verification. Most Fortune 500 organizations, Microsoft-hosted domains, and companies using enterprise email security run catch-all configurations. Without resolution, you're leaving your most valuable prospects on the table — or risking your sender reputation sending to unverified addresses.

Sales teams doing enterprise outbound

Stop skipping C-suite prospects at Fortune 500 companies because their domain is catch-all.

RevOps teams cleaning CRM data

Resolve the 40%+ of your contact list that other verifiers mark as "unknown."

Agencies managing client deliverability

Offer catch-all resolution as a premium verification service your clients can't get elsewhere.

Clay users building enrichment waterfalls

Add catch-all validation as the final step in your waterfall to maximize coverage.

40%+of enterprise emails are catch-all

Microsoft-hosted domains, Fortune 500 companies, and organizations using Proofpoint or Mimecast. These are your highest-value prospects.

~0%bounce rate on resolved emails

When LeadMagic resolves a catch-all email to "valid," it delivers. Pay-per-result means you only pay for conclusive results.

100%security gateway compatibility

Works with Proofpoint, Mimecast, Barracuda, Cisco IronPort, and every other Secure Email Gateway on the market.

Available everywhere you build

REST API

18 endpoints, sub-200ms response. Integrate enrichment directly into your stack.

Learn more

CLI

One command to install. Enrich CSVs, query data with AI, automate from your terminal.

Learn more

MCP Server

16 enrichment tools inside Cursor, Claude, VS Code, and 10 more AI assistants.

Learn more

FAQ

Frequently asked questions

Unlock your risky leads

Start verifying catch-all emails today. Get 100 free credits to test it. No credit card required.

Get your API key Read the docs

Catch-All Email Verification — Resolve 'Unknown' to Valid or Invalid

Catch-all emails are killing your campaigns

Delayed Bounce Rates

Enterprise Domains Are Catch-All

Security Gateways Block SMTP

How Catch-All Validation works

Submit catch-all emails

Advanced verification

Get verified results

Advanced verification for risky emails

Why "catch-all detected" isn't enough

How verifiers handle catch-all domains

Who needs catch-all verification?

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Enrichment APIs

Available everywhere you build

REST API

CLI

MCP Server

Frequently asked questions

Unlock your risky leads