Super Refer A Friend is plugin which adds a new widget to your blog which allows readers to email the page they are on to a friend via a popup box.
They can enter more than one email address and customise the message that is sent.
The plugin includes a captcha and you can set a mailing limit to prevent spam
Support at http://wplift.com/refer-a-friend-wordpress-plugin
1) Download the plugin.
2) Extract it. After extraction, there will be a folder named “super-refer-a-friend”.
3) Place it in your plugin directory.
4) Login as admin to your blog site.
5) Activate the plugin.
6) Go to “Widgets” section. There you will see the widget as “Super Refer A Friend”.
Add it to your desired sidebar. You can customize the various options of the widget
from its widget customization form after placing the widget in sidebar.