/Email deliverability/Open Relay Test

Open Relay Test

Probe whether the mail server accepts mail for external recipients without auth.

smtp › relay probe
Mail server or domain
Tip — type a command to jump tools:relay:mail.acme-corp.io
Try one
What this checks
01Connecting on port 25
02EHLO handshake
03MAIL FROM external
04RCPT TO external
05Reading the verdict