A blacklist is list that contains IP addresses and domains that are believed to send spam. Emails from these IP addresses or domains are either blocked or sent to the recipient’s spam or junk mail folder. Blacklists are used by organizations like ISPs, email service providers and spam filtering service providers to identify and block spammers.
Anti-spam software or spam filtering software usually use these lists as one of the ways of blocking spam from being delivered to recipients mailboxes. Some anti spam software also have provision for the IT administrator of a business to blacklist specific senders once identified as spammers.
Read this article for more information on:
How blacklisting works. This is especially important for companies who rely heavily on email marketing.
Types of blacklists and blacklisting.
How businesses end up on email blacklists.
How to know if you have been blacklisted.
How internet service providers use spam traps to blacklist spammers.
Email marketing best practices that help avoid blacklists.
How to delist from an email blacklists,