Identify accept-all mail servers that hide whether mailboxes exist. Assess bounce risk before you send and protect your sender reputation.
Standard SMTP verification cannot tell real from fake addresses on catch-all domains. Our multi-probe detection identifies these servers so you can make informed sending decisions.
Catch-all domains accept every incoming email — even to addresses that don't exist.
The mail server accepts any address at the domain, making it impossible to confirm whether a specific mailbox is real.
Standard SMTP checks always return 'valid' — only actual delivery reveals the bounce later.
Lists with undetected catch-all addresses carry a 30–50% higher bounce rate risk over time.
Spam traps are often hosted on catch-all domains, making them nearly impossible to detect without specialized probing.
Multi-step SMTP probing identifies accept-all servers with 99% accuracy.
MX records and mail server configuration are resolved and analyzed for catch-all indicators.
Multiple probes with known-invalid random addresses test how the server responds to nonexistent mailboxes.
Server response patterns are analyzed to distinguish true catch-all from normal acceptance behavior.
Each domain gets a risk confidence score based on probe results and sending risk classification.
99%
Detection Accuracy
Multi-probe SMTP analysis
30–50%
Higher Bounce Risk
Undetected catch-all domains
<3s
Detection Time
Per domain analysis
100
Free Daily Checks
No credit card required
Each tool addresses a different email risk type.
Check individual emails for validity, deliverability, and reputation. No account required.
Identify and block temporary email services before they pollute your list.
Detect emails likely to bounce before sending, protecting your sender reputation.
Filter out generic role addresses like info@, support@, and admin@ that hurt engagement.
A catch-all domain accepts emails sent to any address, even nonexistent ones. You cannot tell which mailboxes are real, so sending to them carries a higher bounce risk over time.
We send SMTP probes to the domain's mail server and test how it responds to known-invalid addresses. If the server accepts everything, we flag it as catch-all. This method achieves 99% accuracy and never sends actual emails to recipients.
It depends on your risk tolerance. Catch-all addresses carry 30–50% higher bounce risk. We recommend segmenting them into a separate list and monitoring performance closely before scaling sends.
Our catch-all detection achieves 99% accuracy using multiple SMTP verification methods. We distinguish true catch-all servers from temporary configurations to give you reliable results.
Yes. Upload a CSV to check thousands of addresses at once. You can also use the real-time API for on-the-fly detection. Both methods return the same structured JSON result.
Yes. You get 100 free checks per day, no credit card required. The API also has a free tier so you can test the integration before committing.
Catch-all email verification is the process of detecting whether a mail server accepts messages for any address at a domain — regardless of whether the specific mailbox exists. A catch-all (accept-all) server never returns a rejection during SMTP handshake, making it impossible to confirm individual mailboxes. BillionVerify identifies catch-all domains, assesses their bounce risk using historical delivery data, and flags them so you can decide whether to include them in your campaign.
An accept-all email address belongs to a domain whose mail server accepts every incoming SMTP connection — even for non-existent mailboxes. This means standard verification cannot confirm whether the address is real. 'Accept-all' and 'catch-all' mean the same thing. BillionVerify detects accept-all domains, scores their historical bounce risk, and helps you decide which addresses are safe to send to versus which should be excluded.
Identify catch-all servers, assess bounce risk, and improve deliverability before you hit send.
100 free checks daily · 99% detection accuracy · No credit card required
