Glossary
Email relay
A server that accepts mail and passes it on to another server.
ValidReach Team · Updated 2026-10-26
In practice
Organisations use relays to send from applications through one controlled point. An open relay, which accepts mail from anyone for anyone, is quickly abused for spam and gets blocklisted, so relays should require authentication.
Verification and sending
Not a verification topic; relays affect how a message is routed after you send it.