SPF

Sites

• http://www.openspf.org/

Docs

• http://en.wikipedia.org/wiki/Sender_Policy_Framework
• http://homepages.tesco.net/J.deBoynePollard/FGA/smtp-spf-is-harmful.html

FAQ

Check SPF record of a host

dig domain.com TXT

SPF - Returned fail

Misconfigured SPF record or spoofed "From" address