to backup outlook files, you have to check the location of your pst files and copy it to anywhere else.
( to know where your pst files exists, in outlook open tools–> options–>mail setup–>account settings–> data files click on the path and click open folder)
you can’t copy an pst file unless outlook was closed.
for automation you might use any backup software, or you can make your own through a batch file containing copy command
and then add the batch file to a windows scheduled task (programs–> accessories–> System tools –> scheduled tasks)
hoping i was helpfull
You can also turn on auto-archiving in tools – options – other. But also remember to right-click every folder and select “archive this folder”. The subfolders are not archived by default. You can set the archive to run every so many days or weeks or months. Default setting is to archive items older than 3 months, but of course you can change that to whatever you wish.