When an external dns provider is set in the console menu, it may interfere with some blaclists activated here (RHSBL and DNSBL). the black.uribl.com is well know to bounce all emails in this case with a rejection message deliver to the sender. You can in this case
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When an external dns provider or an internal dns-forwarder is set in the console menu, it may interfere with some blaclists activated here (RHSBL and DNSBL). the black.uribl.com is well know to bounce all emails in this case with a rejection message delivered to the sender. You can in this case