Sometimes these default utilities of Microsoft would not be able to perform well due to certain factors. In that case use of any professional EDB to PST converter can be beneficial.
You can also try below mentioned steps for exporting PST file:
To Export a Mailbox to a .PST file
Once the above is finished, you now have your computer set up to
remotely manage your Exchange 2007 environment. Exporting a mailbox
to a .PST file is as easy as these following steps:
Open up the Exchange Management Shell
Run the following command to to grant full access to the mailbox to be archived:
Add-MailboxPermission -Identity username -User Admin -AccessRights
FullAccess Where ‘username’ is the mailbox that needs to be exported
to a .PST file and where ‘admin’ is the account that is running the
commands from, i.e.; probably your own account.
- Run this command to export the mailbox to a .PST file:
export-Mailbox -identity username -PSTFolderPath X:\Path\filename.pst
Where X:\Path\filename.pst is the location where you want the .PST
saved to and filename.pst is the name of the .PST file.
That’s all there is to it. If the mailbox is large this process can
take some time so be patient. You will see it progressing.`