A blacklist is a list of domains or electronic mail addresses that are believed to be sending unwanted and unsolicited messages to people. If a website or an email address is part of this list, it implies that the particular domain or email address is blocked (i.e. no further message or mail can be received from them.
Whether manually or created by Software, the blacklists are often compiled from identified spam and from other blacklists. There are generally hundreds of blacklists on the internet developed by various volunteers and public organisations who want to maintain a cleaner internet. It is also possible for businesses to have their own private blacklists with information about blacklist sites.
Download the complete guide via this link: