http://www.gentoo.org/proj/en/infrastructure/spf.xml says: For Gentoo, our SPF record is currently: Code Listing 1.1: gentoo.org SPF record v=spf1 mx ptr ?all but this is not the case: $ dig TXT gentoo.org ; <<>> DiG 9.8.3-P1 <<>> TXT gentoo.org ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40686 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 3, ADDITIONAL: 1 ;; QUESTION SECTION: ;gentoo.org. IN TXT ;; ANSWER SECTION: gentoo.org. 3190 IN TXT "v=spf1 mx ptr include:%{l}.%{o}.spf.gentoo.org ?all" ;; AUTHORITY SECTION: gentoo.org. 45533 IN NS ns2.gentoo.org. gentoo.org. 45533 IN NS ns3.gentoo.org. gentoo.org. 45533 IN NS ns1.gentoo.org. ;; ADDITIONAL SECTION: ns1.gentoo.org. 364 IN A 140.211.166.189 ;; Query time: 16 msec ;; SERVER: 62.241.198.245#53(62.241.198.245) ;; WHEN: Tue Sep 10 00:30:16 2013 ;; MSG SIZE rcvd: 162
Fixed, per-user details in the developer email doc.