StopBouncingHow it works
From upload to clean list
in under 5 minutes
No technical setup. No integrations required. Upload your list, we verify every address, you download the results.
Try it freeStep 01
Upload your list
Upload a .csv, .txt, or .xlsx file containing one email address per row. Column headers are detected automatically — no reformatting needed. You can also paste emails directly from a spreadsheet.
- Supports CSV, TXT, XLSX
- Any list size — no hard limit
- Column auto-detection
- Duplicate removal included
Step 02
We verify every address
Our engine runs six verification checks in parallel on every email address — from basic syntax all the way to live SMTP handshake verification against the actual mail server.
- Syntax & format check
- DNS / MX record lookup
- SMTP mailbox check
- Disposable email detection
- Catch-all domain detection
- Role account detection
Step 03
Download clean results
Download your verified list as a CSV with a status column added: valid, invalid, unknown, or disposable. Filter and export only the addresses you want to keep.
- CSV download with status column
- Filter by any result type
- Original data preserved
- Ready to import anywhere
Under the hood
Six checks. Every email. Every time.
Each address goes through all six checks before a result is assigned. The order matters — we stop at the first definitive negative signal.
Check 01
Syntax validation
We check that the address is correctly formatted — no double dots, invalid characters, or missing @.
Check 02
Domain & MX record lookup
We verify that the domain exists and has valid mail exchange (MX) records configured to receive email.
Check 03
SMTP mailbox check
We simulate sending a message and check whether the specific mailbox exists on the mail server — without actually delivering any email.
Check 04
Disposable email detection
We flag addresses from known temporary email services (Mailinator, Guerrilla Mail, 10 Minute Mail, and thousands more).
Check 05
Catch-all domain detection
Some domains accept any incoming address regardless of whether the mailbox exists. We detect these and mark them as 'unknown' — never invalid.
Check 06
Role account detection
Addresses like info@, admin@, support@, and no-reply@ are often shared inboxes with low engagement. We flag these so you can decide whether to include them.
What each result means
And what to do with it.
The mailbox exists and is accepting messages. Safe to send.
→ Include in your send list.
The address does not exist, has a bad format, or the domain has no MX records.
→ Remove from your list immediately. Sending to these will bounce.
We cannot definitively confirm the mailbox — typically a catch-all domain, temporary provider outage, or SMTP-blocking provider.
→ Proceed with caution. Never discard these as invalid — they may be real.
The address belongs to a temporary or throw-away email service.
→ Remove if you want engaged, long-term users. These addresses are almost never active for more than a few hours.
Your data is safe — and temporary
Every uploaded file is processed on EU-based servers and permanently deleted within 48 hours of processing. We do not retain, analyse, or sell your email data. Verification happens in memory; nothing is written to long-term storage beyond the result status.
See it in action
Start with 100 free verifications — no credit card needed.