Aah, so I see… 3 backquotes… So I was able to run the command and now apt update works fine: zarafa-meetings:~# curl https://USERNAME:PASSWORD@download.kopano.io/supported/core:/final/Ubuntu_16.04/Release.key | apt-key add - % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 100 3102 100 3102 0 0 507 0 0:00:06 0:00:06 --:--:-- 675 OK I’m betting the problem is that a username/password is required to get the key so the basic apt-key command won’t work. Thanks Bob