E-Mail Blacklists <Moderate>

Blacklists are becoming a hot topic around HQ. They are lists of hosts that at some point have produced a large amount of Spam. In the case of most of our clients, this is usually because of an e-mail virus.

The first symptom that your site has been blacklisted is that e-mail stops flowing to certain people. Big companies usually use multiple lists to decide whether or not to accept a message. Depending on their configuration, your site may need to be on only 1 or 2 lists to be denied e-mail access.

To check if you have been blacklisted, we recommend checking:

http://www.mxtoolbox.com/blacklists.aspx or

http://www.blacklistalert.org

Each of these sites checks multiple Blacklists to see if your host has been listed. To get your host IP address, check:

http://www.whatsmyip.net

Interesting Statistic:

• According to the CBL (Composite Blocking List), only 28% of 30,000 unique daily infections are detected by the top 35 most popular AV products.