From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040207 Firefox/0.8 Description of problem: SPF permits MTAs to verify that the sending MTA is a permitted source of mail for a given domain by checking dns txt entries. SPF is gaining widespread adoption, including large ISPs. For a system to fully participate, its MTA must be able to validate SPF for received mail. Sendmail milters or patches are available to support this. I would like to see SPF support provided in RHEL (presumably by milter until sendmail supports it natively) see http://spf.pobox.com Version-Release number of selected component (if applicable): How reproducible: Always Steps to Reproduce: 1. n/a 2. 3. Actual Results: n/a Expected Results: n/a Additional info:
SPF is patented, therefore there is no way to put it in.
I think you are mistaken - are you possibly thinking of the Microsoft Sender ID, which does have patent issues. I believe Sender Policy Framework (SPF) is open, and has now been adopted by the IETF. see http://spf.pobox.com