Knowledgebase: Outbound Mail Flow
My IP is an OPEN RELAY error
Posted by Elvin C, Last modified by David Szoke on 05 January 2018 07:14 PM

Issue: Receiving a bounce error or see in your logs: "IP Address is an open relay."

Note: This issue confirms that your set-up for outbound relay is configured properly through the Proofpoint Essentials smarthost, otherwise you would not be seeing this error.

Description: A relay test is periodically done against a customer's sending IP. These are the "Sending Servers" found in the Domains tab. The test we perform against these IPs is to check if your IP allows us to send/relay from a domain not found in your "Domain" list. 

  • If your system only allows relays from your domains, it will fail our open relay test, and you do not receive the above error.
  • If your system allows any domain to send, we consider this an open relay. You can check your mail logs for this issue.

Secure your mail server: Per the test, your system is allowing any domain not in your "Domain" list to send. You can do multiple things from your mail server side.

  • Create rules to only allow your valid domains to send
  • Do not allow relay for outside connections

These are only suggestions, and you can secure your mail server as needed.

How can I retest? The periodic check is automated.

How can I relay again? Upon a re-test by our automated system, if our test fails then your IP will be allowed relay again. Unfortunately, if our system still is able to relay, then the IP will continue to be blocked. 

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