Definition of BLACKHOLDS, RBL or DNSBL
RBL (Realtime Blackhole List) or DNSBL (Back List DNS) are lists of servers or networks known to assist, host, produce or retransmit spam, or provide a service that can be used as a medium for sending spam.
RBL (Realtime Blackhole List) or DNSBL (Back List DNS) are lists of servers or networks known to assist, host, produce or retransmit spam, or provide a service that can be used as a medium for sending spam. Mailsafe uses the main community and commercial RBLs on the market.
Not all blacklists are created equal. There are currently over a hundred public RBLs available on the Internet, as well as private blacklists (accessible by subscription) and even proprietary blacklists (not accessible). RBLs can be set up according to a variety of criteria: spamtrap (honeypots of deliberately erroneous e-mail addresses), DUL (ISP networks), IP definition, manual denunciation, antispam tools, blacklisted IP classes, open relay server, IP belonging to certain countries, server not complying with RFCs, etc.