Nov 9th, 2009
Sender Policy Framework (SPF)
Sender Policy Framework (SPF) is a relatively new method of fighting spam. As more time passes, this protocol will be used as one of the standard methods of fighting spam on the internet. Essentially, an SPF record is a type TXT record placed into a domain’s DNS zone. The string placed within the TXT record specifies a list of authorized host names/IP addresses that mail can originate from for a given domain name. Once this entry is placed within the DNS zone, no further configuration is necessary to take advantage of servers that incorporate SPF checking into their anti-spam systems. These are added the same way as a regular A, MX, or CNAME record would be.
A typical example TXT record for SPF looks like this:
serverbuddies.com. IN TXT “v=spf1 a mx ~all”
source for this information can be found here: http://www.openspf.org/SPF_Record_Syntax
SPF Record Testing Tools
http://www.kitterman.com/spf/validate.html
