"Host": It is the internet address of your mailbox server. This information should be able to be found inside the account setup page of your mail account. For example, the one for Gmail is "pop.gmail.com". Then one should type in the user name and password for the corresponding account. Choose to check the "Remember" checkbox on the right. This allows the system to keep the password for you so that you do not need to enter it every time it is needed.