How to customise the confirmation email
To customize the confirmation email go to your campaign dashboard > Settings > Confirmation email.
From there, you can change the look & feel, the body, the subject and the "From" name of the email.
Use the special merge tag %confirmation_link% where you want the button to appear.
To preview the email, click on the tab "Preview" in the top right corner.
Don't forget to save the changes when you're done!