Is a “catch-all domain” the same as a valid address?

Myth: False. A catch all domain accepts mail to any address at that domain, including nonexistent addresses. This is a server configuration choice, not validation of specific addresses.

Catch all domains hide bounces since the server accepts everything. This can obscure invalid address problems in your list. Addresses at catch all domains may exist, may not, or may be monitored spam traps.

Validation tools flag catch all domains because deliverability cannot be verified. Treat catch all addresses with caution, especially if acquired through uncertain means.