Visitors to your site are able to sign up to receive your newsletters. These people don't have profiles on your site and as a result won't appear in the User Accounts/Profiles section of your admin. In order to see the email addresses and names of these people you can download an excel compatible CSV file.
From your 'Account Home' page locate the 'Newsletter Sender' panel and click the 'Export Subscribers' option. This will cue the CSV file to download to your machine.
The tutorials here aim to help you make the most of your SSPWebsite. We aim to expand this section to become a one stop shop for both you and your fellow site users.