Altera Mailbox Core and multiprocessor communication

Hi

I have successfully instantiate multiprocessor in my design and now i want to somehow send some message between the processors
In the Altera embedded IP document there is an IP core called "Mailbox" which used to send the message between the processors
I'm using Quartus 12.1 and in the QSYS there is no mailbox core available
Altera change the core name or just removed the core?
What is an alternative option for sending message between multi NIOS II Processor?

Please give me some suggestion