#http://www.tecmint.com/setup-postfix-mail-server-in-ubuntu-debian/
apt update && apt upgrade -y
apt-get install -y postfix bsd-mailx dovecot-imapd dovecot-pop3d procmail
#internet facing
service postfix restart
service dovecot restart
chmod 1777 /var/mail #to allow deleting of mail

vim /etc/postfix/master.cf #change line to be fifo for mailx
pickup    fifo  n       -       -       60      1       pickup

####Creating Mail Users####
useradd myusername
passwd myusername
mkdir -p /var/www/html/myusername
usermod -m -d /var/www/html/myusername myusername
chown -R myusername:myusername /var/www/html/myusername

#open ports
iptables -A INPUT -p tcp --dport 25 -j ACCEPT
iptables -A INPUT -p tcp --dport 110 -j ACCEPT
iptables -A INPUT -p tcp --dport 143 -j ACCEPT
iptables -A INPUT -p tcp --dport 993 -j ACCEPT
iptables -A INPUT -p tcp --dport 995 -j ACCEPT

#setup virtual mail boxes
vim /etc/postfix/virtual
myusername@domain myusername
postmap /etc/postfix/virtual
vim /etc/postfix/main.cf
virtual_alias_maps = hash:/etc/postfix/virtual
service postfix reload

vim /etc/postfix/main.cf
mailbox_command = procmail -a "$EXTENSION"
service postfix reload
#####Procmail will not send to root and will go to /var/mail/nobody####

#if you want mail to go to users home dir
vim /etc/procmailrc
DEFAULT=$HOME/mail/

#mail is in /var/spool or /var/mail
#If you faced any other error.. Just check the “/var/log/mail.log” file, all the error message will be stored there, you won’t lose your way :)