這個怎麼解釋呢?

FAIL Open relay test
WARNING: One or more of your mailservers appears to be an open relay. If so, this means that you are allowing spammers to freely use the mailserver to send out spam! It is possible that your mailserver accepts all E-mail and later bounces it, or accepts the relay attempt and then deletes the E-mail, but this is not common.
WARNING: supercase.com appears to be an open relay: 250 Not.abuse.see.www.DNSreport.com.from.IP.210.75.29.190@DNSreport.com... Recipient OK
這是把我們的郵件服務器作為中轉站了嗎?