Create mailbox by FIM 2010 R2

Hi all,

I'm trying to use FIM 2010 R2 to do provisioning mailbox on Exchange 2013

According to some article on Internet I use that command in MVRule to create mailbox

csentry = ExchangeUtils.CreateMailbox(ManagementAgent, component, nickname, mailboxMDB);

But it doesn't work. I can see the HomeMDB has changed as the string mailboxMDB on the command, but the mailbox couldn't be created.

Anyone please help me. Thanks !

p/s: Is that possible if I use something simple like enable-mailbox in MVRule to create mailbox automatically after the user is created on AD?