Postfix

apt-get install postfix
      General type of mail configuration: **Internet Site**
      System mail name: **cometpass.com**

vim /etc/postfix/main.cf
      myhostname = mailto.example.com
      mydestination = localhost.localdomain, localhost
/etc/init.d/postfix restart

https://help.ubuntu.com/community/Postfix

RDNS

IP <=> mailto.cometpass.com

SPF Record

example.com TXT "v=spf1 a:mailto.example.com ~all"

log

tail -f /var/log/syslog      

send report

apt-get install pflogsumm

cron job
/usr/sbin/pflogsumm /var/log/mail.log > /var/www/postfix.txt

pop3

apt-get install dovecot-postfix