

There are online backup services that can backup pst files when Outlook is open and incrementally backup the pst, so only changes are saved.

If you shut the computer down before its completely uploaded then try to open it from another computer, the pst may be corrupt. While you could use OneDrive or another cloud service to store backup copies of your data files, its not recommended due to the large size of many pst files: uploading a large data file can take "forever". This is an unsupported scenario and Microsoft will not provide support for it.

Can i use google drive for mac without keeping files on my computer full#
DropBox does incremental backups (reducing the need to upload a large pst in full each time), however, you need to make sure you close Outlook and wait for all updates to be uploaded before shutting down the computer, otherwise accessing the pst from another computer could result in lost data or a corrupt message store.
