Click on the button 
to access the configuration window for sending emails.
Use E-Mail reaction? : Activate the sending of messages by mail
SMTP Server : Enter the SMTP server address
Mail to : allows you to fill in the email address (es) to contact. Separate them with a "; "
Mail from : to enter the desired name for the mail sender.
Confirm the settings with the "OK" button, or cancel with the "Cancel" button.