Why Catch-All Email Domains Fool Verification Tools Into False Positives

A catch-all email domain is configured to accept messages sent to any address at that domain, regardless of whether the specific inbox exists. Standard verification methods like syntax checks and MX record lookups confirm only that the domain can receive mail, not that a particular local address is valid or monitored. Even SMTP probing fails to distinguish real from fake inboxes on catch-all domains, since the server returns a positive response to every query by design. Some verification services flag such domains as risky and reduce their scores, but this risks discarding legitimate business contacts like sales@ or info@ addresses. Experts suggest the better approach is to lower confidence scores for catch-all addresses rather than rejecting them outright, treating the issue as a confidence problem rather than a validity one.