Adding another mailbox to Outlook (Windows application)

One can add multiple mailboxes to Outlook in order to more efficiently manage emails from various accounts in one place. 

To do this, launch Outlook, then click 'File' -> 'info' -> 'Add Account' 

Pop in the additional mailbox's email address and password when prompted. Tick to remember the password (so you don't get prompted to login whenever you open up Outlook)

Close and reopen Outlook in order to refresh the mailbox list - it may prompt for an initial login again; pop the details in and tick to remember again.