ciphermethod.com

Install Postfix:
yum install postfix (RedHat)
apt-get install postfix (Debian)

Add Domains to Accept Mail For:
vi /etc/postfix/main.cf
set
mydestination = localhost.localdomain, localhost, domain.com, host

Tell Postfix to use Maildir instead of mbox format:
postconf -e "home_mailbox = Maildir/"
postconf -e "mailbox_command ="

Set MAIL variable in /etc/profile:
export MAIL=$HOME/Maildir

Restart Postfix:
service postfix restart

Mail local user and confirm mail is delivered.

Install Dovecot:
apt-get install dovecot-common dovecot-imapd dovecot-pop3d