Verify the configuration for spam quarantine releases:
Check the domain portion of the TO: Address (The part after the @ sign of the TO: Address). This is the domain we are trying to contact when we release the message.
- To determine where releases from quarantine will be delivered, verify the configuration in (Administration > Control Center > SMTP).
- Two options can be selected, "Use existing non-local relay settings" or "Define new host".
- "Use existing non-local relay settings" uses the Outbound Non-Local Mail Delivery settings under (Administration > Configuration > Select the "Local Host" > SMTP > Outbound)
- If Outbound Non-Local Mail Delivery is set to "Use MX lookup for non-local domain mail" then a DNS MX record lookup will be done to determine where messages released from quarantine will be delivered.
- If Outbound Non-Local Mail Delivery is set to "Relay non-local mail to the following hosts" is selected then we are going to deliver all messages released from quarantine to those IP addresses.
- When "Define new host" is selected, then messages released from quarantine will be delivered to that IP and port.
The default is to use "Outbound Non-Local Mail Delivery" settings, which is usually configured to "Use MX Lookup for non-local domain mail". Which means all email will be delivered based on MX records for the domain.
- In order to use this option, your internal DNS server need to have an internal MX record for each of your internal domains. This means when SMG does an MX record lookup your "domain.com" all configured DNS servers must return an IP address of an internal mail server that will accept messages for that domain.
- If you use "Define new host" and is directed to internal mail servers, you will not be able to release messages that are destined for external domains. The control center will attempt to deliver them to your mail server, which is likely not configured to accept email for that domain. All local mail will be accepted and all non-local (external) will be rejected and will return an error and remain in quarantine.