After you finish installing eM Client you will be automatically asked to set up your first account. You can use the Automatic setup or open the other tabs to explore manual setup options. 

To set up additional email accounts go to Menu > Accounts section and create new accounts using the '+ Add account' button.

To explore the setup options in more detail please read the Create New Account page from our online documentation or check out specific account types in the Compatibility section on our website.