Assuming the system is Centos / Redhat system.
Steps:
Step 1:
Create virtual file lets say “all_email_forwarder” for email forwarding inside /etc/postfix/
vi /etc/postfix/all_email_forwarder
To forward all outgoing emais, lets say ” myemail@domain.com”, please do the following:
/.+@.+/ myemail@domain.com
Step 2:
Edit /etc/postfix/main.cf file and add /edit virtual_maps variable with the following:
virtual_maps = regexp:/etc/postfix/all_email_forwarder
Step 3:
restart postfix service:
service postfix restart