Determination of SPF records for the intention of sending spam

As more than 70% of the total email traffic is spam, it creates a significant problem in the usage of email service. None of the methods to fight against this problem are perfect. Content-based filtering techniques for spam recognition require considerable amount of computational resources. For this reason network-based filtering is gaining importance in spam fighting. Sender Policy Framework (SPF) is a protocol that can provide an efficient network-based filtering technique. As SPF usage is growing up, it is seen that spammers are also using that framework. They prefer to use the SPF records of newly purchased domain names. Only way to prevent those spams is using blacklist or content filtering. In this paper, by comparing DNS/SPF records of spam sending domain names and ham sending domain names distinctive properties are tried to be found.