Most validators mark catch-all domains and greylisted servers as "unknown" and give up. HeroBounce resolves them - recovering the leads your current tool leaves behind.
100 free validations • No credit card required
Connects with your entire stack via REST API
Catch-all domains and greylisted servers account for a large portion of B2B email - and most validators return “unknown” without attempting to resolve them.
Catch-all domains account for 30-40% of all B2B email addresses. Standard validators return “unknown” and stop - leaving a significant portion of every list unactionable.
Large organizations routinely configure catch-all DNS as a security measure. “Unknown” does not mean invalid - it means your validation tool reached its limit.
Valid / Invalid / Unknown forces a choice between protecting sender reputation and discarding qualified pipeline. HeroBounce resolves the ambiguity.
Clean your email lists in 3 simple steps
Drag & drop your CSV file. We support lists of up to 10,000 emails per upload.
Our engine checks syntax, DNS, MX records, and SMTP - then actively resolves catch-all and greylisted emails instead of marking them unknown.
Get a clean list with confidence scores on every email - not just valid/invalid/unknown - so you can make informed decisions.
The only validator that solves the "Catch-All" problem.
| Feature | HeroBounce | Competitors |
|---|---|---|
| Greylisted Email Handling | Auto-retry (~87% resolved) | Unknown |
| Catch-All Resolution | 50-70% Resolved | Unknown |
| Accuracy Guarantee | 95%+ | 95% |
| Pricing / 10k emails | $25$17 | $65+ |
| Domain Intelligence | ||
| Pattern Discovery |
Stop guessing and start knowing. Our enterprise-grade verification engine gives you the confidence to hit send.
We don't just say 'unknown' - we analyze patterns, domain behavior, and historical data to give you real answers.
Sub-second API responses with smart caching. Verify 100,000 emails in minutes, not hours.
Identify spam traps, complainers, and toxic addresses before they damage your sender score.
Greylisted servers temporarily reject unknown senders before accepting them. We automatically retry - resolving ~87% of greylisted emails within 20 minutes at no extra cost.
Validated domain configurations are cached for 90+ days. Repeat domains resolve significantly faster and with higher confidence as our knowledge builds.
Clean REST API with SDKs for all major languages. Start integrating in minutes.
Trusted by 500+ sales and marketing teams