When I create a new user and click on ' Send test Email ' . It throws an exception ' Failed to send email titled "Mango test email" to "firstname.lastname@example.org". Message: "Mail server connection failed; nested exception is javax.mail.MessagingException: Could not connect to SMTP host: localhost, port: 25; nested exception is: java.net.ConnectException: Connection refused: connect" ' .I open the Email settings in System settings but I dont know what I can enter in SMTP host and From address . Any help ? Also should I check the Enable TLS box ? What is it used for ?