What is a blacklist?

When searching for an email validation service many marketers have often been listed on a blacklist and are trying to remedy the situation.

A blacklist is the compilation of information by an organization. This “list” is compromised of individuals or information that should not be trusted or interacted with. In email marketing blacklists deal with IP addresses, domains, and individuals that are know or believed to send SPAM.

There are hundreds of blacklists operating, some more important as far as email delivery, others not so much. The reason for getting listed on a blacklist will vary depending on the operator or organization. Too many hard bounces, backscatter, affiliate SPAM, incorrect mail records, spam traps or honeypots, or UCE (unsolicited commercial email) are just a few reasons for a listing. Some organizations are more vindictive and will list legitimate mailservers for no good reason.

The best tool to see if you have been listed on a blacklist is http://multirbl.valli.org.

Out of the hundreds of blacklists several will have a major impact on email delivery. We go over these in another post you can find here.

ISP’s, network administrators and webmasters use blacklists as tools to block bad incoming mail. If an IP address, domain, or range is found on certain blacklists mail will be denied or blackholed.

Blacklists can be automated or dynamic, falling off after a certain period of time should the SPAM stop. Others are manual or need to be delisted by making a request.

Blacklists use a number of methods to determine whether or not an IP or mailing domain is sending SPAM. The most common methods are honeypots or spamtraps. Others may include a recipient reporting abuse or monitoring bad mail through internal or third party tools.

Spam traps can either be created by anti-spam professionals for the sole purpose of receiving and monitoring SPAM. These are published on websites or never published online. Abandoned email addresses can be recycled as well, after a period of dormancy, and used to detect mail being sent to old email addresses. This helps identify those who are not removing hard bounces from their email lists.

If you are encountering issues with blacklists you will need to validate your email list.