TABLE 1: Typical Spam Source Types
Source Type	Additional Information
Confirmed spam source	The RBL provider has identified the source as a constant source of spam.
Default	The RBL provider has identified the source as a spammer or other problematic source.
Dial-up spam source	The RBL provider has identified the source as a dial-up connection (or another source with a dynamically assigned IP address) that has been used to send spam.
Open proxy server	The RBL provider has identified the source as an open proxy that has been used to send spam.
Smart host	The RBL provider has identified the source as a secure site that serves as a relay for unsecured sites.
Spamware developer or site that uses spam to advertise	The RBL provider has identified the source as a developer of spamware or a vendor who hires spammers.
Verified open relay	The RBL provider has identified the source as an open relay.