Turn Time Machine on to back up your Outlook items
# On the Apple menu, choose System Preferences>Time Machine.
# In the Time Machine dialog box, switch Time Machine to On, then choose Select Backup Disk.
# Select the location where you want to back up your files, and then choose Use Disk.
# Ensure Time Machine is set to Back Up Automatically.
Your files will now back up daily.
***This May Help,***
***Peter***