Reverse sync mail.app mailboxes to gmail?

[sloburn]

backstory: my hdd died recently . I use mail.app to check my gmail. I organized my mail in mailbox folders. The dead drive experience led me to realize my mail was only sorted in mail.app on the drive, not on webmail.

Question: I have a backup of the mail folders and i want to have my mail sorted both locally and on the web. Is there a way to sync my mail.app created folders to gmail so that my sorts and folders will show up in gmail?

Or, am i stuck having to create a new folder system in gmail and resorting all my emails, then syncing that to mail.app?

Thanks for your kind input.