About 1 in 4 validations lands on a catch-all domain. HeroBounce flags them, explains why each address is risky, retries greylisted servers, and lets you download each group separately - so you decide what to send.
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About 1 in 4 validations on HeroBounce lands on a catch-all domain, and some lists are heavily greylisted. A plain valid / invalid answer hides what you most need to know about 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 adds the reason, so you can decide per segment.
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 flags catch-all addresses with a reason and retries greylisted servers.
Get a clean list with confidence scores on every email - not just valid/invalid/unknown - so you can make informed decisions.
Catch-all addresses are flagged, explained and exported as their own list.
| Feature | HeroBounce | Competitors |
|---|---|---|
| Greylisted Email Handling | Auto-retry after ~15 min (subscription plans) | Varies |
| Catch-All Handling | Flagged + reason + own list | Varies |
| Reason for Every Result | status + sub_status | Varies |
| Pricing / 10k emails | $17 (20,000 included) | Varies |
| Domain Intelligence | Varies | |
| Pattern Discovery | Varies |
Stop guessing and start knowing. Our enterprise-grade verification engine gives you the confidence to hit send.
We don't leave catch-all addresses as a shrug: we analyze patterns and domain behavior and tell you why each one is risky.
Single checks typically take a second or two, and repeats are served from cache. Bulk jobs run live SMTP verification on every address - real checks, not pattern-matched guesses.
Identify spam traps, complainers, and toxic addresses before they damage your sender score.
Greylisted servers temporarily refuse unknown senders. We retry automatically after about 15 minutes at no extra credit, and about 1 in 5 completed retries ends in a definitive valid or invalid.
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.
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