below is the error message:
Content-Type: message/delivery-status
Reporting-MTA: dns; localhost.localdomain
Received-From-MTA: DNS; it-wordpress
Arrival-Date: Wed, 26 Nov 2014 15:20:01 +0800
Final-Recipient: RFC822; XXXXXXXX@yahoo.com
Action: failed
Status: 5.1.3
Diagnostic-Code: SMTP; 553 5.7.1 [BL21] Connections will not be accepted from 112.199.67.38, because the ip is in Spamhaus's list; see http://postmaster.yahoo.com/550-bl23.html