>products and they think there should be something with the mail server >itself to prevent spaming. I am wondering if there is some special >setting to do this.
Yes, there is. Jim DeHaven may give me hell for pointing you at the documentation, but I'm sorry. I can't help myself. :)
Go to
http://www.spiderisland.com/docs/
Enter "spam" into the search field, and you'll quickly find 3 pages of documentation that cover the problem.
If there is a problem undertanding what the docs mean, pls let me know.