Hey Joe,
Thank you so much for your help. We are using Macs & gmail.
It's not working yet though.
So the IP address of the printer is 192.168.0.19, which is close to the ones from our computers (read somewhere that that might be important).
I checked the DNS & Default gateway of the router, they were already correct in the settings.
Subnet 255.255.255.0
Gateway: 192.168.0.1
I put the 3 DNS addresses in the (empty) spaces where it said (additional) DNS addresses (and put them in the right order).
68.105.28.11
68.105.29.11
68.105.28.12
Few questions about the options that I might have to turn on/off
Should I prefer ipv6 above ipv4?
IP-Address is now on STATIC, or should that be bootp or dhcp?