Open relay
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(Redirected from Open relays)
An open mail relay is an SMTP (email) server configured in such a way that it allows anyone on the Internet to relay (i.e. send) email through it.
[edit] Third Party Relaying
An SMTP open relay is a mail server that permits an unknown, outside sender to pass mail through the server to unknown, outside recipients, usually without the consent of its manager.
This gives professional spammers a ready delivery mechanism for dumping unsolicited commercial email (UCE) on undeserving end-users while avoiding detection.
It's easy to see why spammers favor open relays. They can abuse other people's bandwidth and mail servers, without getting blocked, blacklisted, or suffering negative publicity.
