The three groups represent a combined membership of more than 1,500 e-mail marketing companies.
"We believe that a DNE Registry would do nothing to deter spammers, and in the long run would penalize legitimate marketers by making their efforts costlier and more time consuming," Greg Stuart, president-CEO of IAB, said in a statement. "We are also firmly convinced that through the efforts of our groups, that the industry can achieve workable solutions to this problem."
The groups said they believe technological challenges would make a do-not-e-mail registry "impossible to enforce, prohibitively expensive and difficult to secure." The companies on Tuesday released a white paper on the subject, which can be downloaded from http://www.espcoalition.org/resources.php.