Also known as: Accept-All Domain
A mail server configured to accept email for every possible address at a domain, even ones that do not exist.
A catch-all (or "accept-all") domain is configured to accept mail for any address at the domain — [email protected] — rather than rejecting addresses that do not have a real mailbox. Companies use catch-alls so that misspelled addresses still reach someone.
Catch-alls are the hardest case for email verification. Because the server accepts everything during the SMTP conversation, a verifier cannot tell a real mailbox from a non-existent one by probing alone — the answer is "yes" either way. An honest verifier reports these as catch-all with lower confidence rather than guessing "valid."
BounceShift flags catch-all results separately and leans on its crowdsourced reputation data — real delivery and bounce outcomes from connected mail streams — to raise or lower confidence on catch-all domains instead of pretending to be certain.
The process of checking whether an email address is real, correctly formatted, and able to receive mail before you send to it.
The standard protocol mail servers use to send and receive email across the internet.
An email address used by mailbox providers and blocklists to identify senders with poor list hygiene.
A trust score that mailbox providers assign to your sending IP and domain, which determines whether your mail reaches the inbox.
See it in action
Check any address against BounceShift's multi-layer engine — syntax, MX, disposable, and role checks free, with full SMTP verification on signup.