Adding virtual user for Postfix
 

Hi,
I have Postfix mailserver with virtual domains. It 's running good. However, I have to create a system user in to be able to use postfix. I'm trying to create a virtual postfix user account(not system user) but don't know how to do it. I've read a lot of document about it but still don't understand it. Could anyone please walk me through step by step.

Thanks