Google won an important and rare victory on Thursday, when the European Court of Justice (ECJ) ruled that its Gmail service should not be treated as a telecommunications service, dismissing arguments made by Germany's telecoms regulator.

The ruling means that Google will not be required to register Gmail as a telecoms service and will escape the vast range of data protection and security obligations that apply to telecommunications companies in Germany.

The decision is a victory for Google and other so-called over-the-top (OTT) service providers that feared the burden of being treated the same way as telecommunications companies.

In 2015, Google challenged a decision by Germany's telecoms regulator, the Bundesnetzagentur, to classify its Gmail services as a telecommunications service. The Higher Administrative Court in Cologne, Germany, asked the ECJ to decide whether Gmail met the requirements to qualify as a telecoms service. These are defined in EU and German law as transmitting electronic signals.

The ECJ found that Gmail's service did not "wholly or partially consist" of the transmission of signals. Although the sending of emails via Gmail involved the transmission of signals, the signals were transmitted by internet service providers, not Google itself, the court found.

"The ECJ rightly points out that not every service which includes the conveyance of signals on electronic communications networks automatically falls under the stringent EU telecoms regulatory framework," said Christoph Werkmeister, a lawyer with Freshfields Bruckhaus Deringer in Düsseldorf.

If the ECJ had ruled in favour of the German regulator, Google and other providers of web-based email services could have faced a range of regulatory requirements that apply to telecommunications service companies.

These include obligations to share information about data transfers with law enforcement authorities, as well as the possibility of being forced to make their services interoperable with other web-based services.

New EU legislation due to come into effect at the end of 2020, known as the European electronic communications code, is expected to apply to OTT services and impose stricter regulatory requirements on them.

Google did not immediately respond to a request for comment on the ruling.