si.Mail's main window displays the application menu and toolbar and a tabbed view of the message classification system. 

The Compose mail window lets you select the mail account to use, enter the recipients and write the mail subject and actual message. 

si.Mail's Account menu lets you select the action you want to perform from a wide list that includes Manage rules, Fetch messages, Send messages, Account properties, etc. 

The Message menu provides you with various message actions, like New message, Reply, Assign categories, Create rule, Mark, Label and others. 

In the Language Settings window, you can select the preferred language from the list of the ones available. 

The Security Settings tab enables you to choose the appropriate security level and to select an antivirus application to check messages. 

The Spam Settings tab allows you to customize some options related to the mark messages as spam process. 

In the View window, you can configure the application's appearance in order to fit your taste. 

The Task Bars Settings window lets you enable/disable various options about the application toolbars. 

The Other Settings window allows you to customize the application's behavior according to your needs and preferences.