Can’t send emails due to failed internal dns resolution

Now when i changed quotation marks, and wanted to rebuild app, it told me to update the Docker. Now Im unable to rebuild an app cause of that:

fatal: unable to access 'https://github.com/SamSaffron/pups.git/': Could not resolve host: github.com

Changing DNS and restarting docker like described here didnt solve it.

Getting more and more frustrated…