A BROWSER MALWARE TAXONOMY

This restriction of IP space for mail solves one problem but it doesn’t solve others. On the one hand, it makes management of IPs scalable for machines that are bots. Today, most spam is sent from botnets. However, botnets do not always send out all of their spam directly – many bots compromise legitimate mail hosts or email accounts and send out spam that way, or create a throwaway account at a free email service and send out small amounts of spam from it before discarding it. This technique is used today but on a smaller scale than spamming directly. If we successfully solve the problem of direct-to-spam botnets, spammers will simply shift the bulk of their spamming to compromised or throwaway accounts.