StopBouncingBad emails cost you more than you think.
Every bounce damages your sender reputation. Let it climb past 2% and your ESP flags your account — or suspends it without warning. StopBouncing verifies your entire list before you send, catching invalid, disposable, and catch-all addresses so your campaigns actually land.
100 free verifications · No credit card · Lists deleted within 48 h
Checking syntax · MX records · SMTP · disposable providers · catch-all
Works with
One bad send can end
your email program
Email service providers enforce bounce thresholds without warning. The damage compounds faster than you expect.
2% bounce rate. Your ESP flags your account.
Mailchimp, SendGrid, Klaviyo — all of them enforce bounce thresholds. Exceed 2% and deliverability drops immediately. Let it climb further and your account is suspended.
Future campaigns go to spam — even to your best subscribers.
Inbox providers score your sending domain continuously. A damaged reputation doesn't reset after one campaign. It compounds, silently burying your emails for months.
Months of warm-up. Lost revenue. Reputation recovery isn't guaranteed.
Getting unsuspended requires manual review. Reputation recovery requires months of low-volume warm-up sends. All of it avoidable with a one-time list clean before you sent.
The fix costs as little as €0.0005 per address — less than any consequence above.
2–5%
Average bounce rate on unverified lists
6
Verification checks per email
€0.0005
Per address at volume
48 h
Maximum data retention
15–25%
of any email list decays every year
People change jobs, abandon inboxes, sign up with throwaway addresses. Without verification, your list silently rots between campaigns.
2%
bounce rate is where ESPs start watching
Mailchimp, SendGrid, Klaviyo, and Brevo all enforce bounce thresholds. Exceed them and your account is flagged — or suspended without warning.
40%
higher open rates after list cleaning
Fewer bad addresses means more of your mail lands in inboxes, your reputation scores improve, and engagement metrics go up across the board.
Clean any list in three steps
No technical knowledge required. Works for 100 addresses or 10 million.
How verification works →Upload your email list
Drop a .csv or .txt file — one address per row. We auto-detect the email column. Duplicates are removed before processing starts.
We run 6 verification checks
Syntax · DNS/MX records · SMTP mailbox · disposable email detection · catch-all domain · role account detection. Every address, every time.
Download your clean list
Get a CSV with a status column: valid, invalid, unknown, or disposable. Import directly into Mailchimp, Klaviyo, or any other tool.
Six checks.
One clean list.
Every address passes through the full verification pipeline — every time, automatically. How it works →
10,000 emails verified in under 3 minutes
Upload a CSV and walk away. Our engine processes your entire list in parallel — syntax, DNS, live SMTP — and hands you back a clean file ready to import.
Block fake signups before they touch your database
One API call at sign-up. Under 2 seconds. Invalid addresses and disposable emails are rejected at the door — not discovered after your first campaign.
The deepest check available — without sending a message
We simulate an SMTP handshake against the actual mail server to confirm the mailbox exists. No real email sent. No trace left. Maximum accuracy.
Catch-all and disposable addresses — never falsely removed
Mailinator, Guerrilla Mail, and thousands of burner providers are flagged automatically. Catch-all domains are marked unknown — so you never incorrectly drop a real contact.
API keys per environment — revoke in one click
Create separate keys for dev, staging, and production. Label them, monitor usage, revoke instantly. Hashed at rest. Full audit log in the dashboard.
No monthly fee. No expiry. Pay only when you verify.
From €0.0005 per email at volume. Buy credits when you need them — for a campaign, a quarterly clean, or a one-off scrub. Credits never expire.
From €0.0005 per email at volume
No subscription · Credits never expire · 100 free on signup
Your next campaign deserves a clean list.
Verify your first 100 addresses free. See exactly what's in your list before it damages your sender reputation.
Need more than 1,000,000 addresses? Contact us for volume pricing