Xtreme - Version 3.a The Power Packed Email List Manager Software For The Responsible Online Marketer! Xtreme Email List Manager was created for the responsible internet marketers, and provides individuals/companies with the tools to manage databases of email addresses. This allows companies to better maintain client lists and to market their products/services more effectively. Because people are constantly changing their email addresses, there exist a need to handle this constant change and Xtreme makes this an easy task.