Frogster mostly only blocks the former Soviet Union block, I think. En Masse also blocks Japan (maybe), China, Russia(n region), Middle East, and Africa.
"En Masse has a license to operate TERA game servers in North America. This means that if you are in North America, South America, Europe (excluding Russia), and Oceania (Australia, New Zealand, Micronesia, Melanesia, and Polynesia) you can play on En Masse Servers."
Source