LeadList Verifier vs MillionVerifier
MillionVerifier is the cheapest per-email verifier on the market. LeadList Verifier is the verifier that finishes the job on catch-all addresses. Below: what each tool actually does with the hardest segment of your list, and the real per-list cost math.
Quick verdict
Choose MillionVerifier if
You verify B2C lists or B2B lists with low catch-all density, per-email cost is the primary decision criterion, and unresolved catch-all addresses don’t hurt your campaigns.
Choose LeadList Verifier if
Your lists are B2B-heavy where catch-all addresses dominate the unresolved segment, you need every address turned into a verdict, and per recovered deliverable lead is the metric you actually care about.
The core difference
The catch-all marketing problem.
MillionVerifier advertises catch-all verification as a feature. Read the marketing pages and you’ll see catch-all listed alongside syntax checking, MX lookups, and disposable detection. The reality is more nuanced: MillionVerifier detects that a domain is configured as a catch-all and returns “catch-all” as the result status. The specific mailbox itself is never verified.
This is detection, not resolution. From the buyer’s perspective, the address looks exactly like an unresolved address. You can’t safely send to it. You can’t safely discard it. On a B2B list where catch-alls sit on roughly 25 to 30 percent of addresses, that “catch-all” bucket becomes the bottleneck.
What MillionVerifier returns
alex@orbital.tech
Domain accepts mail for any address. Mailbox status unknown.
What LeadList Verifier returns
alex@orbital.tech
Two-pass engine verified the specific mailbox behind the catch-all domain.
How resolution works
How LeadList Verifier resolves catch-alls.
The two-pass engine treats catch-all detection as an intermediate signal rather than a final answer. Pass 1 is a primary SMTP verification engine that handles syntax, DNS, MX lookups, and standard mailbox probes, the same work MillionVerifier does. When Pass 1 flags an address as catch-all, the result feeds into Pass 2.
Pass 2 is a proprietary catch-all resolution engine. It probes the specific mailbox behind the catch-all domain using techniques that go beyond a single SMTP RCPT TO check, including waterfall routing, signal aggregation across multiple verification vectors, and provider-aware probes for Microsoft 365, Google Workspace, and Proofpoint catch-all configurations. The output is a definitive verdict: deliverable, undeliverable, or risky, with a numeric confidence score.
MillionVerifier
LeadList Verifier
Where MillionVerifier excels
- Cheapest per-email pricing on standard verifications. Hard to beat on flat unit cost.
- Mature SMTP verification logic with years of production use.
- Strong on B2C addresses and clear-cut B2B mailboxes (non-catch-all).
- Simple credit-pack model with no subscription.
Where MillionVerifier struggles
- Catch-all domains: returns 'catch-all' status with no mailbox-level resolution.
- Yahoo and AOL addresses: well-documented accuracy issues with conservative results.
- No deliverable / risky / undeliverable verdict for the catch-all segment.
- Per-list cost looks cheap until you count the unresolved catch-all leads.
Real cost math
Per-list cost, not per-email cost.
MillionVerifier wins on per-email cost. That’s real and unambiguous. The fairer comparison for B2B work is per recovered deliverable lead, because the catch-all segment is where the economics flip.
Consider a 10,000-address B2B list with a typical 25 percent catch-all rate. MillionVerifier resolves the 7,500 clear-cut addresses and flags the 2,500 catch-alls. Those 2,500 are effectively lost, you can’t send to them safely. LeadList Verifier runs the same primary pass and then resolves the catch-all segment in the second pass, typically returning around 72 percent (1,800 of the 2,500) as verified deliverable.
MillionVerifier on the 10K list
$24
LeadList Verifier on the 10K list
$55
The relevant metric
MillionVerifier delivers usable leads at $24 / 5,800 ≈ $0.0041 each. LeadList Verifier delivers usable leads at $55 / 7,600 ≈ $0.0072 each. But the MillionVerifier number leaves about 1,800 deliverable leads on the table that LeadList Verifier recovers. For most B2B outreach economics, recovering those leads pays for the price difference many times over.
Numbers assume a 25 percent catch-all rate and 72 percent second-pass resolution. Catch-all rates vary by industry and list source. B2C lists typically have much lower catch-all density, which is why MillionVerifier remains the right call for those use cases.
Features
Feature comparison.
| Feature | MillionVerifier | LeadList Verifier |
|---|---|---|
| Catch-all address verification (mailbox-level) | No, flags only | Yes, two-pass |
| Catch-all returns deliverable / risky / undeliverable verdict | No | Yes, with confidence score |
| Primary SMTP verification | Yes | Yes |
| Yahoo / AOL accuracy | Known issues | Strong |
| Bulk CSV upload | Yes | Yes |
| Real-time API | Yes | Yes |
| Webhook delivery | Yes | Yes |
| Free credits on signup | 100 | 100 |
| Subscription required | No | No |
| Credit expiration | Never | Never |
| Per-email cost at 10K | $0.0024 | $0.0055 |
| Per-email cost at 1M | $0.00039 | $0.0019 |
Pricing
Pricing at common volumes.
MillionVerifier is cheaper per email. LeadList Verifier costs more because the second pass on the catch-all segment is real additional work. The right framing isn’t which is cheaper outright, it’s which delivers more usable leads per dollar on your list.
| Volume | MillionVerifier | LeadList Verifier |
|---|---|---|
| 10,000 emails | $24 | $55 |
| 100,000 emails | $90 | $360 |
| 1,000,000 emails | $390 | $1,899 |
Pricing as of May 2026. Verify current MillionVerifier pricing on millionverifier.com. LeadList Verifier pricing page.
FAQ
Common questions.
What does MillionVerifier actually do with catch-all addresses?
MillionVerifier detects that the receiving domain is configured as a catch-all and returns 'catch-all' as the result status. The specific mailbox itself is not verified. Buyers receive a list of addresses they can't safely send to and can't safely discard.
How does LeadList Verifier handle catch-all addresses differently?
LeadList Verifier's two-pass engine treats catch-all detection as an intermediate result rather than a final answer. A proprietary second pass probes the specific mailbox behind the catch-all domain using techniques single-pass verifiers don't run. The result becomes deliverable, undeliverable, or risky with a confidence score from 0 to 99.
Is MillionVerifier still useful if I use LeadList Verifier?
If you only need standard SMTP verification on B2C lists or B2B lists with low catch-all density, MillionVerifier is genuinely cheaper per email. If your lists are B2B-heavy where 25 to 30 percent of addresses sit on catch-all domains, the per-list math flips because LeadList Verifier recovers the segment MV leaves unresolved.
Why is LeadList Verifier more expensive per email?
Running a proprietary catch-all resolution engine on the catch-all segment costs more than a single SMTP check. The fair comparison isn't per email, it's per recovered deliverable lead. On a typical B2B list, MV resolves 70 to 75 percent of addresses. LeadList Verifier resolves 95+ percent. The 20-point recovery on the catch-all segment is what you're paying for.
Can I use both together?
Many teams do. Run MillionVerifier on the bulk list to handle standard mailboxes cheaply, export the catch-all segment, and run that segment through LeadList Verifier. The recovered deliverable addresses merge back into the campaign list. The combined per-list cost stays competitive and the deliverable count goes up.
How accurate is the catch-all resolution?
On production B2B lists, the second pass returns a confidence-scored verdict on more than 72 percent of catch-all addresses. The remaining segment stays marked risky with a numeric score, so you can decide whether to send based on your own risk tolerance.
Do I have to commit to a subscription?
No. Both verifiers use credit packs without subscriptions. LeadList Verifier credits never expire, same as MillionVerifier.
Resolve your catch-alls.
Re-run the catch-all segment of your MillionVerifier export with 100 free credits. See how many come back deliverable.