If you are using email for work, you are most likely using an Exchange or IMAP account. Exchange and IMAP servers automatically archive your email so that you can access it anytime or anywhere. If you have an Exchange account, check with your admin about how to access your archived email.
If you want to back up the message folders locally, you can export the items to a .pst file that you can restore later as needed and use by importing.
Back up your email in Microsoft Outlook:
Select File > Open & Export > Import/Export.
Select Export to a file, and then select Next.
Select Outlook Data File (.pst), and select Next.
Select the mail folder you want to back up and select Next.
Choose a location and name for your backup file, and then select Finish.
If you want to ensure no one has access to your files, enter and confirm a password, and then select OK.