It is possible....If abc is an user.....
For that you have to do like this...
Edit /etc/aliases file and add an entry....
root: root,abc
From that all mails from root will be forwarded as a copy to abc@example.com
If you need all other copy of all users simply add in /etc/aliases
user: user,root
From abv the user mails will be forwarded as a copy to root....
If anythis pls mail me........