More links about SPF

SPF: Sender Policy Framework
The Anti-Forgery solution that's making the world a safer place for email.

MTA Authorization Records in DNS (marid) WG
It would be useful for those maintaining domains and networks to be able to specify that individual hosts or nodes are authorized to act as MTAs for messages sent from those domains or networks. This working group will develop a DNS-based mechanism for storing and distributing information associated with that authorization.

The SPF Setup Wizard
Most domains send outbound mail through a relatively small number of servers. Domains should describe that set of servers in an SPF record in their DNS. Internet email receivers can then reject forged messages which don't come from an envelope sender domain's approved servers. This wizard helps domain owners identify all the servers which could be expected to send mail from their domain.

libspf2 - Home
libspf2 implements the Sender Policy Framework, a part of the SPF/SRS protocol pair. libspf2 is a library which allows email systems such as Sendmail, Postfix, Exim, Zmailer and MS Exchange to check SPF records and make sure that the email is authorized by the domain name that it is coming from. This prevents email forgery, commonly used by spammers, scammers and email viruses/worms.

Microsoft to enforce Sender ID checks
Microsoft Corp. will soon put some bite into its Sender ID antispam plans by checking e-mail messages sent to its Hotmail, MSN and Microsoft.com mail accounts to see if they come from valid e-mail servers, as identified by the Sender ID, according to a company executive.