One bad send on a fresh domain and you're blacklisted. BounceZero removes invalid, catch-all, role, and disposable addresses before your first email goes out — so your domain reputation survives the warm-up.
With newsletter or transactional email, a small bounce rate is manageable. With cold outreach on a new domain, the margin for error is almost nothing.
You start with no sender history. ISPs have no data to say you're trustworthy. High early bounces confirm their worst assumption — that you're a spammer with a dirty list.
Newsletter senders can attribute some bounces to subscriber churn. Cold outreach has no such defense — every bounce signals poor data practices.
Many cold email senders use shared IP pools (Instantly, Smartlead, etc.). Blacklisting flows to neighbors. Keeping your bounce rate low protects your pool.
Beyond basic SMTP — the signals that matter for cold outreach specifically.
SMTP handshake confirms the specific mailbox is active at the mail server — not just that the domain exists.
Three-probe method fingerprints servers that accept all mail. Catch-all addresses are flagged as Risky — essential for cold outreach where every bounce counts.
info@, sales@, support@, admin@ — role accounts have low personal engagement and high complaint rates. Filtered by default.
800+ provider database identifies throwaway addresses that will never engage.
Confirms the domain has properly configured mail exchange records. Missing MX = 100% bounce.
Cross-references known pristine and recycled trap addresses. A single trap hit can blacklist your sending domain.
Recently registered domains and domains with poor sending history are flagged — common in scraped lead lists.
BounceZero's infrastructure handles greylisting transparently — addresses that require retry are resolved correctly rather than reported as unknown.
Pull your leads from Apollo, Clay, LinkedIn Sales Navigator, Hunter, or your CRM. Export as CSV with email column.
Drag and drop your CSV. BounceZero processes up to 500K emails per batch. Results ready in minutes.
Download a clean CSV with verdict per address: Valid, Invalid, Risky (catch-all/role), Unknown. Sort by verdict.
Keep Valid. Remove Invalid. For cold outreach, skip Risky/catch-all too — the conservative choice that protects your domain.
Load your cleaned list into your sending tool (Instantly, Smartlead, Lemlist, etc.) knowing your bounce rate will stay under 0.5%.
100 free verifications monthly. No credit card. Results in minutes.
Start FreeAlso see our ROI Calculator to estimate what bad emails are costing you.
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