layout – What is the best practice for large quantities of options in an HTML form?

I've inherited from an old web application, which includes an HTML form. This form contains a long list of checkboxes to answer yes or no to the selection of countries to receive updates.
Screen capture

Obviously, this is not the best practice because you can not even see the full list (72 options plus a selection of all).

Are checkboxes in a grid the most user-friendly way to present this information? I've also considered a map with the counties labeled and the option to enable / disable the counties.

Any contribution on this subject is appreciated.