Import Export Exchange 2010 Role to a particular user open an Exchange Management Shell and enter the following command:

New-ManagementRoleAssignment –Role “Mailbox Import Export” –User “userName”

Export Mailbox To PST File Open An Exchange 2010 Management Shell And Enter The Following Command

New-MailboxExportRequest -Mailbox "administrator" -Filepath "\\ServerName\c$\PST\administrator.pst"

 Import PST File Into Mailbox Enter The Following Command

New-MailboxImportRequest -Mailbox "administrator" -FilePath "\\ServerName\c$\PST\administrator.pst"

Check The Status Of The Import Request Get-MailboxImportRequest