[1] [CITE@ja[Sender Policy Framework - Wikipedia]]
([TIME[2009-09-27 09:05:23 +09:00]] 版)
<http://ja.wikipedia.org/wiki/Sender_Policy_Framework>

[2] [CITE@en[RFC 6577 - Authentication-Results Registration Update for Sender Policy Framework (SPF) Results]]
( ([TIME[2012-07-02 02:43:00 +09:00]] 版))
<http://tools.ietf.org/html/rfc6577>

[3] [CITE@en[RFC 6652 - Sender Policy Framework (SPF) Authentication Failure Reporting Using the Abuse Reporting Format]]
( ([TIME[2012-08-16 05:09:52 +09:00]] 版))
<http://tools.ietf.org/html/rfc6652>