See also PowerDNS

See also SSMTP

See also ConfigServer Security & Firewall (CSF)

http://www.thatfleminggent.com/2009/08/09/getting-a-powerdns-recursor-up-and-going-fast

http://windowsitpro.com/networking/secure-your-dns-servers

https://kb.isc.org/article/AA-00874/0/Best-Practices-for-those-running-Recursive-Servers.html

http://www.microsoftnow.com/2013/10/hosting-your-public-dns-servers-on-windows-azure.html

apt-get install pdns-recursor

vim /etc/powerdns/recursor.conf

allow-from=0.0.0.0/0
forward-zones=internal.yourdomain.com=10.0.0.20
local-address=127.0.0.1,123.123.123.123
log-common-errors=yes