A fairly straight forward way has been introduced in Exchange 2010 to import PST’s into mailboxes from the Exchange Shell. Mailbox import requests were added into Exchange 2010 in SP2.
Give yourself permission to use Mailbox Import Requests:
New-ManagementRoleAssignment –Role “Mailbox Import Export” –User Administrator
Import PST (Allowing 49 bad items before the transfer fails):
New-MailboxImportRequest -Mailbox Usermailbox -BadItemLimit 49 -FilePath\\SERVER\SHARE\SOMEPST.PST
Import PST into an Online Archive:
New-MailboxImportRequest -Mailbox Usermailbox -BadItemLimit 49 -IsArchive -FilePath\\SERVER\SHARE\SOMEPST.PST