// Glossary
Catch-All Domain
A domain configured to accept mail for every address, so a mailbox-level verification can't confirm a specific inbox exists.
Definition
A catch-all (or accept-all) domain is set up to receive mail sent to any address under it, even ones that were never created. Because the server accepts everything during an SMTP check, verification tools can't confirm whether a specific mailbox truly exists, so these addresses are usually flagged as risky or unknown rather than valid. Sending to catch-alls carries a higher bounce and spam-trap risk.