sudo apt-get update
sudo apt-get install postfix
sudo nano /etc/postfix/main.cf
remove the alias_maps parameter and replace it with virtual_alias_maps!!
virtual_alias_maps = hash:/etc/postfix/virtual
sudo nano /etc/postfix/virtual
@example.com yourusername
sudo service postfix restart
sudo apt-get install mailutils
How To Install and Setup Postfix on Ubuntu 14.04 :
https://www.digitalocean.com/community/tutorials/how-to-install-and-setup-postfix-on-ubuntu-14-04
How To Install and Configure Postfix on Ubuntu 16.04 :
https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postfix-on-ubuntu-16-04
Setup mail server on ubuntu 14.04 ( Postfix – dovecot ) :
http://www.krizna.com/ubuntu/setup-mail-server-ubuntu-14-04/
PostfixBasicSetupHowto :
https://help.ubuntu.com/community/PostfixBasicSetupHowto
GNU Mailutils :
http://mailutils.org/manual/html_node/Reading-Mail.html
firewall!!! sudo ufw allow Postfix
https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-postfix-on-ubuntu-16-04