Choose POP3 as Incoming and enter pop.stepping-stone.ch as Server hostname. Enter smtp.stepping-stone.ch as Outgoing Server hostname and your Email Address as Username. Check that Port, SSL and Authentication are set to Autodetect and click on Re-test.

Verify that the Incoming Port is set to 110, the Outgoing Port to 587 and both SSL STARTTTL and both Authentication Normal password. Finally you create your account with a click on Create Account.