Google Inc., GOOG -0.20% Facebook Inc. FB +1.69% and other American technology companies were put on the defensive when Edward Snowden's allegations about U.S.-government surveillance of Internet traffic emerged this spring. Outside the U.S., some companies and politicians saw an opportunity. Three of Germany's largest email providers, including partly state-owned Deutsche Telekom AG, DTE.XE -0.28% teamed up to offer a new service, Email Made in Germany. The companies promise that by encrypting email through German servers and hewing to the country's strict privacy laws, U.S. authorities won't easily be able to pry inside. More than a hundred thousand Germans have flocked to the service since it was rolled out in August.