Is this really necessary for yahoo.com generated e-mail?
0.2 DNS_FROM_RFC_ABUSE RBL: Envelope sender in abuse.rfc-ignorant.org 1.4 DNS_FROM_RFC_WHOIS RBL: Envelope sender in whois.rfc-ignorant.org 1.7 DNS_FROM_RFC_POST RBL: Envelope sender in postmaster.rfc-ignorant.org RCR