Outlook mails/folders form a spezal mailbox

Hello I'm new here.
I have a question.
In my outlook I have 4 diferent mailboxes one is the default and 3 others.
I will read the mails form the mailbox "Machine" and there is a folder like "Archive".
How can I read all subjects in this Mailbox "Machine in the folder "Archive"
Pleas can somebody help me ?