The newsletter is designed to be sent to groups of people. By default the contacts in your Console system is organized by Active, Inactive, Hot Leads, Prospects, and Buyers. You can also create additional groups and assign clients to various groups and send the newsletter to any group or combination of groups you desire.
You can also send a newsletter to just one person, provided you have the newsletter saved as a template. To do this you will go to Contacts > Contact Name > scroll down to section 'Other communications' > click the button to 'Send Email'. You can then choose the newsletter from the drop down list of Newsletter Templates.