Messaging Gateway fails to deliver message with error: 451 4.4.2 [internal] no HELO/EHLO response
All mail to an internal domain gets stuck in the delivery queue with "451 4.4.2 [internal] no HELO/EHLO response" error.
And the maillog also displays error messages indicating that a mail loop has been detected.
Without the corresponding error in the maillog, this document likely does not apply.
2017 Mar 29 18:51:24 PDT (warning) ecelerity:  sieve: Rejecting IP mail loop connection
2017 Mar 29 18:51:24 PDT (info) ecelerity:  ML-REJECT: Rejection on: 10.160.248.103:25,200, sent to host: 10.160.248.103:44561, Audit ID 0aa0f867-b7c7eae000006e60-01-4bb1591c4fb3, 554 IP mail loop detected
2017 Mar 29 18:51:24 PDT (info) ecelerity:  ML-TRANSFAIL: Message ID: 10/00-28256-C1951BB4, Audit ID 0aa0f867-b7c7eae000006e60-00-4bb1591ca73c, Temporary delivery failure, sender: firstname.lastname@example.org, recipient: user@domain., Detail: 451 4.4.2 [internal] no HELO/EHLO response
This issue occurs when the destination domain's MX record or IP resolves to the IP address of the Messaging Gateway itself.
This could be a routing issue where the next hop redirects the email back to Messaging Gateway.
Please ensure that the MX or A record of the destination domain does not resolve to the IP address of the appliance.
If you have configured delivery of this domain using the IP address make sure that the IP address is not the IP address of the Messaging Gateway.
Confirm that the downstream MTA does not route inbound messages back to the Messaging Gateway under any circumstance.
Subscribing will provide email updates when this Article is updated. Login is required to Subscribe
Thanks for your feedback. Let us know if you have additional comments below. (requires login)
This will clear the history and restart the chat.