Hi @Joane Jackson ,
Welcome to our forum.
What does the "outlook personal folders" exactly mean here? Do you mean Outlook email folders in your mailbox? Or your local .pst datafiles?
If you mean the email folders in your mailbox, to store the items in your mailbox to your local disk, using Outlook Import/Export option to back up your mailbox items to local .pst file should be a good method.
If you mean opening .pst files without Outlook desktop client, as I know, the .pst file is a special format file for Outlook desktop client and they can not be used in other mail clients.
As a workaround, I would suggest you to add an Exchange email account(Outlook.com account for example) to your Outlook desktop client, then move all the mailbox items you need into this email account, everything could be synced to your web mail and stored online. When you need to use them in the future, you just need to log in to the web mail of this Exchange email account.
Hope this can be helpful.
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