StopBouncingEmail Verification That Actually Works
Verify every email address before you send. StopBouncing runs six checks per address — syntax, DNS, SMTP mailbox, disposable detection, catch-all identification, and role account flagging — in seconds. Bulk CSV upload or real-time API.
100 free verifications on signup. No credit card required.
How we verify
Six Checks. One Accurate Result.
Each email address passes through a comprehensive verification pipeline. Every check catches different classes of bad addresses.
Syntax Validation
Checks that the address is correctly formatted — no double dots, spaces, or invalid characters.
DNS & MX Record Check
Verifies the domain exists and has properly configured mail exchange (MX) records.
SMTP Mailbox Verification
Simulates an email delivery handshake to confirm the specific mailbox exists — without sending any message.
Disposable Email Detection
Identifies throwaway addresses from thousands of temporary email providers (Mailinator, Guerrilla Mail, etc.).
Catch-All Domain Detection
Detects domains that accept all email regardless of whether the mailbox exists — never falsely marks these as invalid.
Role Account Detection
Flags shared inboxes like info@, support@, or no-reply@ that typically have low engagement rates.
What Each Result Means
StopBouncing returns four possible statuses — each with a clear recommended action.
The mailbox exists and is accepting messages. Safe to send.
The address does not exist or the domain has no MX records. Remove immediately.
Could not confirm — catch-all domain, SMTP block, or temporary outage. Do not treat as invalid.
Temporary address from a throwaway email service. Usually inactive within hours or days.
Verify in Three Steps
Upload your CSV
Drag and drop your email list in any CSV format. Our parser finds the email column automatically.
We verify every address
StopBouncing runs all six checks concurrently — most lists complete within minutes.
Download clean results
Get a CSV with verification status added. Filter by Valid, Invalid, Unknown, or Disposable and export.
Frequently Asked Questions
What is email verification?
Email verification is the process of confirming whether an email address is valid, deliverable, and safe to contact. It goes beyond simple format checking — it verifies the domain has mail records and the specific mailbox exists on the mail server.
How does SMTP email verification work?
SMTP verification connects to the recipient's mail server and simulates the first stage of email delivery. The server responds whether the mailbox exists without an actual email being sent — similar to knocking on a door to see if someone is home, without entering.
Will email verification hurt my sender reputation?
No. StopBouncing's verification process uses industry-standard techniques that do not involve sending real emails. Your sender domain and IP are not involved in the verification process.
How accurate is email verification?
StopBouncing achieves over 98% accuracy on clearly valid and clearly invalid addresses. Catch-all domains (which accept all incoming mail regardless of the mailbox) are flagged as 'unknown' rather than guessed, keeping our accuracy rate honest.
What file formats are supported for bulk verification?
Upload any CSV file with an email column. Our parser automatically detects the email field header — no specific column name is required. Results are available for download immediately after verification completes.
Learn More
How Email Verification Works
Deep-dive into every check we run.
Bulk Email Verification
Verify thousands of addresses at once.
Email Verification API
Integrate real-time verification into your app.
Disposable Email Checker
Detect and filter throwaway addresses.
Catch-All Email Addresses
Understand what catch-all means and how to handle it.
Reduce Your Bounce Rate
Practical strategies to improve deliverability.
Start Verifying Today
100 free verifications on signup. Pay-as-you-go credits from €0.0005 per email. No subscription required.