Keep Bounce Rates Under 1.5%.
Protect Your Cold Sending Domains.
Clean scraped Apollo and LinkedIn lists before launching cold campaigns in Instantly or Smartlead. Stop burning warmed-up inboxes on invalid data.
Why Cold Emailers Can't Afford a 3% Bounce Rate
Google Workspace and Microsoft 365 spam filters are stricter than ever. One dirty list can burn months of mailbox warm-up in a single afternoon.
Google & Yahoo 0.3% Cap
When hard bounces rise above healthy levels or spam complaints approach 0.3%, sender reputation can deteriorate quickly — reducing inbox placement and increasing the risk of spam-folder delivery or blocking.
The Cost of a Burned Domain
Replacing a penalized domain means buying new domains, paying for Google Workspace licenses, and waiting 2–3 weeks for warm-up tools to rebuild sender score.
Scraped B2B Data Decay
Even high-quality B2B databases can contain outdated or unverifiable email addresses. Contacts change jobs, companies change domains, and catch-all servers can make it difficult to confirm whether a mailbox actually exists.
From Raw Scrape to Campaign in 3 Steps
Engineered to fit directly between your data source and your cold outreach sender.
Export From Your Source
Export your lead list directly from Apollo, Clay, Sales Navigator, or any custom scraping script with all custom fields intact.
Scrub in NullBounce
Drop your CSV into NullBounce. Our engine identifies Safe contacts, eliminates toxic spam traps, isolates Risky Catch-Alls, and preserves all custom columns.
Upload to Outreach Tool
Export only Safe (Deliverable) records. Upload directly into your sending sequencer with 100% column alignment and zero format errors.
Built for High-Volume Outbound Teams
Why growth agencies and outbound SDR teams choose NullBounce over legacy verifiers.
🧬 100% Column & Merge Tag Integrity
We never drop custom variables like {{FirstName}}, {{Company}}, or {{CustomIcebreaker}}. Your row order remains identical so you can map results back to CRM tables instantly.
🎯 Catch-All & Role Account Filtering
Sending cold outreach to info@ or support@ triggers instant helpdesk auto-responders and high spam complaint rates. NullBounce tags them as Risky so you only email actual decision-makers.
💰 Unfairly Affordable at Scale
From $15 per 10k down to $0.0003 per contact on high volumes. Save over $550 per 100k batch compared to ZeroBounce
👥 Free Team Sharing for Agency SDRs
Running an outbound lead gen agency? Add unlimited SDRs, media buyers, and virtual assistants to a single NullBounce team account. Share a centralized balance of credits with zero per-seat fees.
Buy Only What You Need. Down to a Single Lead.
Have a list of 11,350 contacts? Don't pay for 25,000. In NullBounce, you buy the exact number of credits your list requires.
Your Contact Lists Are Safe With Us
Enterprise-grade privacy standards applied to every verification job.
256-Bit SSL Encryption
All file uploads, API requests, and downloads are protected by modern end-to-end TLS encryption.
Auto-Wiped in 30 Days
Uploaded lists and validation results are permanently purged from our servers after 30 days. You can also delete them manually at any time.
Zero Data Sharing
We never sell, rent, or share your proprietary lead lists with third parties. Your data is strictly yours.
No Real Emails Sent
Our engine performs technical DNS and SMTP handshakes, terminating before delivery. Your contacts will never receive test messages.
Cold Outreach Verification: Frequently Asked Questions
Practical answers to common outbound deliverability questions.
What is the safe bounce rate threshold for cold email?
You should always keep your cold email bounce rate strictly below 2% (ideally under 1%). Exceeding 2% signals to Google Workspace and Microsoft 365 that you are sending to unverified scraped lists, which triggers automatic domain reputation downgrades.
Should I send cold emails to Catch-All contacts?
For primary outbound domains, we strongly recommend sending exclusively to Safe (Deliverable) contacts. If you wish to target Catch-All leads, segment them into a dedicated secondary domain with warm-up limits to isolate your primary sender reputation from delayed bounces.
Does NullBounce alter my custom merge tags in CSV files?
No. We preserve all custom columns (such as First Name, Company, Title, Website, and Custom Icebreakers) and maintain your exact row sequence. The email address is simply extracted to Column A for seamless VLOOKUP and sequencer compatibility.
Can my entire agency team use one balance of credits?
Yes. NullBounce supports multi-user Team Accounts at no extra charge. Agency founders can invite SDRs, assign Admin/User permissions, and share a central pool of credits without paying monthly per-user seat fees.
Stop Burning Inboxes. Start Landing in Primary.
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