This is an automated email sent to recipients so that they can confirm their will to subscribe. This practice prevents fake addresses and spam traps from being added to your database as subscribed, since only humans actually interested in your newsletter will click the link. The editor resembles that of a common word processor; the button 
will help you get the meaning of every button. Use the button
to activate the link after highlighting the text of the link itself.
Besides the body of the message, parameters you can edit are subject of the email and sender name and email. All these parameters will be viewed by the recipient.