DNS server was installed and I had all domains put into the zone files. Seems there is a bug with ISPConfig3 and the bind9 DNS server which is being used together with ISPConfig3. Here’s a small fix on how to get the DNS server running at all times. Please follow this link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=744304#32 . If you’re asking yourself where I get all my domains from, I can recommend Namecheap. They have all .tld extensions at fair price and has been working for me the past 12 years as registrar for all my international domains. A good idea is to enable two-factor authentication to make it harder for intruders to get their hands on your domains. The SMS arrives instantly. It would be a sad day if one day all my domains were gone alltogether ;-) They also provide you with free DNS servers together with your domain all neat setup in an easy to use web interface. Works pretty well out-of-the-box and they´re not penalized by Google or any other Search Engines around if you´re asking yourself that question. Sometimes it is even more simple just to use their services if it´s an add-on domain for a splash page.