Exchange server 2010 Export Mailbox

To export the mailbox of User A(Alias: User.A) to the folder that has been created C:\UserPST
                 Export-Mailbox -Identity User -PstFolderPath C:\User.pst
To export all the mailboxes from a mailbox database (Database1)
                 Get-Mailbox -Database “Database1” -ResultSize Unlimited | Export-Mailbox -PstFolderPath C:\UserPST 

To Export all the mailboxes from a server (ServerA)
                 Get-Mailbox -Server ServerA -ResultSize Unlimited | Export-Mailbox -PstFolderPath C:\UserPST

To Export all the mailboxes from all the Exchange servers and databases in an Exchange Organization
                 Get-Mailbox -ResultSize Unlimited | Export-Mailbox -PstFolderPath C:\UserPST