Scrubby vs MillionVerifier: validating catch-all emails in 2026

Scrubby vs MillionVerifier: Side-by-Side

These two tools don't compete for the same job. Scrubby validates the 20-40% of B2B lists that sit on catch-all domains, where standard SMTP checks return meaningless results. MillionVerifier cleans the bulk of your list fast and cheap. Teams that treat them as substitutes end up with either burned sender domains or an over-engineered verification stack for emails that didn't need special handling.

How Scrubby Validates Catch-All Emails

Scrubby recovers 20-40% of emails that standard verifiers discard by firing disposable test messages at each catch-all address and tracking what happens, per Scrubby's documentation. Standard SMTP handshakes return false "deliverable" signals on catch-all servers because those servers accept all connections. Scrubby bypasses that by testing actual mail delivery, not connection availability.

Catch-all domains accept all inbound SMTP connections regardless of whether the target mailbox exists. That's the core problem every other verifier sidesteps. You don't know if mail reaches a real person until something physically arrives there. Scrubby's approach is slower and more expensive per credit because it's doing real work.

For outbound teams targeting agencies, consultancies, or mid-market SaaS companies, catch-all rates routinely hit 25-35% of a list. Skipping Scrubby on that segment means leaving verified pipeline on the table or burning sender reputation on addresses that don't deliver. Either outcome costs more than the tool does.

How MillionVerifier Handles Bulk Lists

MillionVerifier processes over 4 million emails per hour at $0.000074 per email for large volumes, making it the fastest bulk verifier available today, per MillionVerifier's pricing page. A 100,000-row list returns clean, invalid, and disposable splits in under 30 minutes. That speed and cost profile has no peer for standard corporate domain verification.

What it doesn't do is validate catch-alls. It marks them "risky" and stops. That's an accurate description of its confidence level on those addresses, not a flaw. If your list is heavy on catch-all domains, you'll end up with a large "risky" bucket that MillionVerifier can't reduce further.

The practical move: run MillionVerifier on the full list first, extract the catch-all segment, then pipe that segment to Scrubby. Your total cost per fully validated email lands around $0.003-0.005. That's still far cheaper than the deliverability damage from sending blind to unverified catch-alls.

Pricing: What You're Actually Paying

MillionVerifier is cheaper per email by two orders of magnitude, but that comparison only holds when catch-all volume is low. The real cost comparison is Scrubby's per-credit cost on the catch-all segment versus the domain replacement and warmup cost when those emails bounce hard at scale.

One burnt sending domain wipes out 6-12 months of Scrubby spend in a single incident. Teams that skip catch-all validation and lose a domain tend to add Scrubby the next time without debate.

Which Tool Belongs in Your Stack

Use Scrubby when catch-all domains make up more than 15% of your target list, which covers most mid-market B2B programs targeting companies under 500 employees. Use MillionVerifier as the first-pass verifier on any large list where standard SMTP checks are sufficient for the majority of contacts.

Use Scrubby exclusively if your list is small (under 5,000 emails), your targets skew toward agencies or professional services firms, or you've already taken deliverability damage from catch-all bounces and need accurate validation from scratch.

Use MillionVerifier exclusively if you're running a hygiene pass on a 100k+ list dominated by enterprise accounts with predictable MX records, or if your historical catch-all rate has been under 10%. If you'd rather not manage this yourself, Modern Inbound handles the full verification and outbound stack for B2B teams.

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Frequently Asked Questions

What's the difference between Scrubby and MillionVerifier?

Scrubby validates catch-all emails by firing real test messages at risky domains. MillionVerifier runs SMTP-based verification at speed and low cost but marks catch-alls as "risky" without testing further. They solve different problems and work best in sequence.

Can MillionVerifier validate catch-all emails?

No. MillionVerifier marks catch-all domains as "risky" and stops. It can't determine individual inbox deliverability on catch-all servers. Scrubby is built specifically for that problem.

Is Scrubby worth the higher cost per credit?

Yes, for teams targeting catch-all-heavy industries. A burnt sending domain costs hundreds to replace and weeks to warm up. Scrubby's credits are expensive per email but cheap compared to deliverability damage at scale.

How many B2B emails sit on catch-all domains?

Typically 20-40% of mid-market B2B lists, with agencies and early-stage SaaS running higher rates than enterprise targets, per common SDR benchmarks.

Can I use both Scrubby and MillionVerifier together?

Yes. Run MillionVerifier on the full list first, then Scrubby on the catch-all segment only. This keeps costs low while maximizing verified deliverability across the whole list.