The following steps might be the solution to your problem:
Step 1: Enable IMAP in your Gmail account and then configure Outlook (or Outlook Express or Windows Live Mail) to sync with your Gmail address via IMAP.
Step 2: Import your Outlook PST file into a Personal folder that is different from your default Gmail Inbox.
To import, click File -> Import And Export -> Import from another program or file. -> Next -> Personal Folder File (.pst) -> Next.
Select the PST file that contains your email, then pick the email folders that you want to import in Outlook and click
Finish.
Step 3: Select the Personal folders that you want to backup online and copy them your Gmail Folder in Outlook.
In the Folder List, right-click the folder you want to copy and click Copy Folder name. Click the Gmail Folder in Outlook to copy that folder in that location. You can repeat the steps as needed for other folders.
These steps should also import the folder names from Outlook into Gmail. Please reply with your results.
Source:
http://www.labnol.org/internet/email...t-backup/1938/