Scrubby.io positions itself as the go-to tool for catch-all email verification - the verification category that every other tool avoids or handles poorly. For B2B cold email lists, where 30-50% of valid domains are catch-all, this is a real gap. This review covers what Scrubby actually does, its pricing, accuracy on catch-all vs standard emails, and whether it is worth adding to your verification stack.
Scrubby.io is a specialized email verification tool focused on one specific problem: classifying catch-all emails. Most standard verifiers - ZeroBounce, NeverBounce, Kickbox - return "catch-all" or "accept-all" and leave it at that. This means you either send to the entire catch-all bucket (and absorb higher bounce rates) or suppress all catch-all addresses (and lose 30-50% of your valid B2B contacts).
Scrubby attempts to go further by sending probe emails to test catch-all addresses and using historical send data from its network to classify whether a specific catch-all address is likely deliverable or not. This is a legitimate approach with real limitations - covered in detail below.
| Volume | Scrubby.io price | BounceZero price | Cost difference |
|---|---|---|---|
| 1,000 emails | ~$8.00 | $4.00 | Scrubby 2× more expensive |
| 5,000 emails | ~$35.00 | $12.50 | Scrubby 2.8× more expensive |
| 25,000 emails | ~$162.50 | $37.50 | Scrubby 4.3× more expensive |
| 100,000 emails | ~$500.00 | $99.00 | Scrubby 5× more expensive |
Scrubby’s singular focus means the product is built around the catch-all problem. The UI is clear, the workflow is designed for catch-all batch processing, and the documentation covers edge cases that generalist verifiers don’t address.
Rather than relying purely on SMTP probing (which catch-all domains always accept), Scrubby uses aggregated send history from its network to assess whether a specific email has received traffic before. This can surface information that pure SMTP verification cannot.
Credits purchased do not expire - useful for agencies who run irregular batch jobs and don’t want to manage monthly minimums or credit rollovers.
The output CSV includes a Scrubby-specific confidence score alongside the standard result buckets, making it easy to apply your own threshold rather than relying on Scrubby’s binary safe/risky classification.
Scrubby is priced for use as a second-pass on catch-all segments, not as a primary verifier. If you try to run entire lists through Scrubby, the cost is 2-5× higher than dedicated verifiers with equivalent catch-all scoring.
Catch-all classification accuracy depends on the richness of Scrubby’s historical send data for a given domain. For newer domains or very niche verticals with few historical senders, results fall back to less-confident estimates.
Scrubby is built around batch uploads, not real-time API validation at point of capture. If you need inline verification at form submission, you need a different tool.
Scrubby does not replace a primary verifier - it does not classify role-based addresses, disposable emails, or syntax errors as a standard verifier does. You must run a full verification first, then pass catch-all results to Scrubby.
Large catch-all batches (100K+) can take several hours because Scrubby is performing real probe attempts and network lookups per email, not just SMTP handshakes.
| Feature | Scrubby.io | BounceZero |
|---|---|---|
| Primary use case | Catch-all second-pass | Full-stack email verification incl. catch-all scoring |
| Catch-all scoring | ✅ Core feature | ✅ Built-in with confidence score |
| Standard verification | ❌ Not included | ✅ 5-stage pipeline (syntax>DNS>MX>SMTP>reputation) |
| Real-time API | Limited | ✅ <200ms median |
| Role-based detection | ❌ | ✅ Included |
| Disposable email detection | ❌ | ✅ 30,000+ disposable domains |
| Price at 25K emails | ~$162.50 | $37.50 |
| Free tier | Trial only | 100 credits on signup |
| Credits expire | No | No |
| Bulk CSV upload | ✅ | ✅ |
| EU data residency | Not specified | ✅ UK servers |
Scrubby.io is an email verification tool specialising in catch-all email validation. It attempts to classify catch-all domain emails as deliverable or not using SMTP testing combined with historical send data. It is primarily used by cold email agencies and SDR teams who have large B2B lists where catch-all domains represent a significant share of contacts.
Scrubby.io pricing starts at ~$8 per 1,000 emails for smaller volumes. At 100,000+ emails the rate drops to around $5 per 1,000. There is no ongoing free plan. Compared to BounceZero’s $3.99-$4.99 per 1,000 with built-in catch-all scoring, Scrubby is significantly more expensive for comparable catch-all coverage.
Scrubby.io reports 96-98% accuracy on standard emails. On catch-all domains, accuracy depends on the richness of its historical send data for the specific domain set. For cold email at scale, pairing a primary verifier with catch-all scoring (BounceZero does this in one step) is more cost-effective than adding Scrubby as a second-pass tool.
BounceZero runs the full 5-stage pipeline and scores catch-all emails in the same pass - no second tool, no double billing. 100 free credits to start.
Ayoub built BounceZero's 5-stage validation pipeline, its dedicated BGP-announced IP infrastructure, and the Patroni HA PostgreSQL cluster behind every verification. Previously built high-volume email delivery infrastructure. Trained at 1337 Benguerir (École 42 network, 2019). Open-source: bgp_analyzer.
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