Exim
Disable IPV6
ipv6-disable
Eximstat
Linux: Debian 8
echo -e "#"'!'"/bin/sh\neximstats -nr -nt -tnl -include_original_destination -bydomain -byemail /var/log/exim4/main.log | mail -s "EXIM statistics" postmaster@domain.com\n#" > /etc/cron.daily/eximstat
chmod +x /etc/cron.daily/eximstat