First off there are 2 ways to do this.

The first one is for the Exchange 2010 NON SP1 and I will not cover it because it involves either dangerous techniques or a second machine with Office 2010 64 bit and Exchange 2010 management tools. You can find the “how to”  here.

The second way is dedicated for Exchange 2010 SP1.

1. Start the Exchange Management Shell

2. Give the user you are logged on with role assignment using the command below. (AdminExchange is my user in this situation)

New-ManagementRoleAssignment -Role “Mailbox Import Export” -User AdminExchange

3. Start he export of the desired mailbox using this command:

New-MailboxExportRequest -Mailbox Jan@domain.nl -FilePath \\Server\share\jan.pst
The mailbox can also be an alias or the full e-mail account and the filepath needs to be a share (if it’s not a share you’ll get an error regarding the path).

If you have a large mailbox it will take longer. Don’t close the management shell until it’s finished.