export Mailbox To Pst File

Hi Everyone,

i am trying to export some mailbox in my exchange2010 Sp3 to Pst , but when excute the below command i got the Error:

New-mailboxExportRequest -Mailbox "admin" -filepath \\ server\Pst\admin.pst

i got the following Error:

The call to 'net.tcp://server name/Microsoft.Exchange.MailboxReplicationService server name' timed out. Error details: This request operation sent to net.tcp:// server name//Microsoft.Exchange.MailboxReplicationService did not receive a reply within the configured timeout (00:01:00).

i tried to increase TimeOut on Client Access folder in Web.config file  i make (DataImportTimeout=00:20:00)but not successfully.

Note: (Pst) folder has been shared and give Group (exchange trust subsytem) full permission.

thank in advance