Start the program "Menu | Internet | SeaMonkey mail and news". The configuration depends on your email-provider. In the following you will find an example for GMX.
After you press the button "Finish" the program automatically downloads your emails from your email account. If you are offline, the following error message appears:
Start an Internet-connection and click (in the Seamonkey-Mail-Programm) on the button "Get new messages".