Over 40% of all emails within your marketing campaign are not being delivered. You may not even be aware of this, as many ISPs will not send back a bounce message. In fact if you are sending messages to AOL customers, AOL is now blocking over 80% of the messages that come into their servers.

One of the main reasons that this is occurring is that your IP or Domain may be Black Listed. All major ISP's and many corporate email systems now check against Black Lists and will refuse to deliver any emails that come from an IP that is Black Listed.

But what exactly is a Black List?

DNS black lists are lists of domains and IP's that are known to originate Spam. Many anti-spam software programs used by corporations and ISP's use these lists to control Spam by refusing any email that originates from one of these domains or IPs.

Unfortunately there are many instances of false positives as there are few checks and often little objectivity when listing a particular IP. In order for a black list to know that a domain is sending Spam, the offence must be reported . It may take only one report via a web form for you to be listed.

You may be listed maliciously through one complaint of a client, or that of a competitor. Many Black Lists, as well, will list not only the IP that is suspected as spamming, but will list any IPs in that range of addresses. If someone using the same Internet provider as you is accused of spamming and is placed on a Black List, you may be listed as well.

DNS blacklists are usually maintained by anti-spam organizations or by individuals.

What are some of the most popular Black Lists that ISPs are using?

Some of these include:

MAPS - http://www.mail-abuse.com/

Spam Cop - http://www.spamcop.net/

SpamHaus - http://www.spamhaus.org/

SPEWS.org - http://www.spews.org/

ORDB.org - Open Relay Database - http://www.ordb.org/

How do I know if I am on a Black List?

Unfortunately, you really can't be 100% sure if you have been black listed. You may be on someone's black list and not even know it. There are, however, ways to check most of the lists.

One way is to check your server log when sending your campaigns. You will often see an email bounce notice indicating that the message has bounced because you are on a particular black list.

Many of the major black lists also allow you to enter your IP into a form on their site. These checks will tell you whether you appear, or not, on their list.

A useful tool, is the Black List Monitor. http://www.blacklistmonitor.com/. - It automatically checks your IP against most of the major Black Lists and tells you which ones you are listed on. It also gives you help in getting removed. All your IPs are constantly monitored for any changes, listings, or delistings.

But what is a White List and how can this help?

Many corporations and ISPs will create a white list. This is a list of trusted IP addresses that they feel confident will not send spam to their customers. If your IP is listed on a particular white list then your email messages will be delivered to the destination email address. It is important for reputable marketers to work with the major ISP's such as AOL to ensure that you are on their white list. For most, it can be a lengthy process, but well worth your efforts.

Other third-party email certification programs now exist. Bonded sender http://www.bondedsender.com/ is one such agency. By joining Bonded Sender, senders improve deliverability rates and differentiate their brand. Senders go through a formal application process, adhere to email standards and post a bond against potential complaints. Major ISPs such as MSN/Hotmail now check against Bond Sender's white list and allow these email to pass.

Knowing if you are on a black list, getting removed if you are and getting established on white lists is critical if you are email marketing. The more messages delivered equals more sales!

Author Karen Fegarty is with MailWorkZ the creator of Black List Monitor-- advanced service that continuously checks all the major blacklists for you, and then some. Don't be treated unfairly! Keep a handle on who may have you blacklisted. Get a free trial and find out more at http://www.blacklistmonitor.com/.