Exim Post-Install 

1. Put this in /etc/rc.conf
exim_enable="YES"
sendmail_enable="NONE"

2. Put this in /etc/mail/mailer.conf
sendmail        /usr/local/sbin/exim
send-mail       /usr/local/sbin/exim
mailq           /usr/local/sbin/exim
newaliases      /usr/bin/true
hoststat        /usr/bin/true
purgestat       /usr/bin/true

3. Put this at end of /etc/newsyslog.conf
/var/log/exim/mainlog   mailnull:mail 640 7 * @T00 Z
/var/log/exim/rejectlog mailnull:mail 640 7 * @T00 Z

4. (optional) Change this in /etc/make.conf
NO_SENDMAIL=true