Glossary
The words a result uses.
Every term here is one the service returns a reason code for. Each definition ends where the guesswork would start — at what the check actually does when it meets the thing being defined.
All terms
Catch-all domain
A domain whose mail server accepts every address at the domain, whether or not the mailbox exists.
Greylisting
A spam defence that temporarily rejects the first delivery attempt from an unknown sender and accepts the retry.
Spam trap
An address that exists only to catch senders who mail people who never asked to hear from them.
Role account
An address that reaches a function rather than a person — info@, support@, sales@.
Disposable email address
A throwaway address from a temporary-mailbox service, created to get past a signup form.
Hard bounce and soft bounce
The difference between mail that will never be delivered and mail that failed this time.
SMTP handshake
The conversation between two mail servers that establishes whether a recipient will be accepted.
MX record
The DNS record that says which server accepts mail for a domain.
See it on a real address.
The free checker returns the whole result — every stage, every reason code, nothing held back.