How to verify emails on catch-all domains

What is a catch-all domain?

A catch-all domain is configured to accept all incoming email — regardless of whether the specific mailbox exists. This means mail sent to anything@company.com will be accepted by the server, even if that address was never created.

Why this makes validation harder

Standard SMTP verification asks the server "does this mailbox exist?" Catch-all servers always say yes, making it impossible to distinguish real addresses from made-up ones at the SMTP level.

How BounceProtect handles catch-all domains

BounceProtect identifies catch-all servers during domain analysis. When a domain is confirmed catch-all:

1. The email is flagged with status "Risky" and reason "Catch-All Domain"
2. SMTP verification is marked as "Unavailable" — because any result would be a false positive
3. The send recommendation is "Send with Caution"

What to do with catch-all results

Catch-all emails are not necessarily invalid — many are real inboxes at companies that just have permissive server configuration. Options:

• Send and monitor: Include them in your campaign but track bounce rates carefully
• Suppress until engaged: Only send to catch-all addresses that have previously opened or clicked
• Use Deep Analysis: Check the company legitimacy score — a catch-all at a verified business is more likely to be a real address than a catch-all at a parked domain