Sending e-mails from the platform doesn't work
Under Windows, you are required to configure the main/inc/conf/mail.conf.php file to use an SMTP server. The file is quite understandable. If you use an SMTP server with authentication, configure smtp_auth to 1 and define a user and a password. If you use an open SMTP server, set smtp_auth to 0.
Under GNU/Linux, you can choose to use an SMTP server like under Windows. Alternatively, if your browser allows it, you can use a local mails server. To configure one under Ubuntu, you can follow the documentation on the BeezNest blog: http://beeznest.wordpress.com/?s=exim4