Estonia quarantines emails from Russian domains over cyberattack risk

Estonia is automatically diverting emails using Russia’s .ru internet domain into quarantine for additional security checks before they reach state institutions connected to the country’s secure government network, Justice and Digital Affairs Minister Liisa Pakosta told Estonia's public broadcaster ERR.

The measure is intended to protect Estonian government computer systems amid a post-2022 surge in cyberattacks that officials link to Russia. It applies only to institutions operating inside the secure state network, leaving local governments and some state bodies outside.

Many Estonian residents, particularly Russian speakers, still use .ru email services, ERR noted. Because the filter is triggered solely by the address ending, legitimate messages will be screened alongside potentially malicious ones and may take longer to arrive.

Pakosta said the safeguard was necessary because cyberattacks against Estonia had increased “exponentially” since 2022 and that many were linked to Russia. She said such attacks had not succeeded against Estonia, while major public-sector cyberattacks had succeeded in both Latvia and Lithuania.

The rerouting is automatic and handled centrally, so agencies do not need to take any action, Pakosta said. A large proportion of state institutions have already moved behind the government’s unified cyber shield, while the transition continues.

Pakosta described the quarantine as one small measure within Estonia’s wider cybersecurity work. Estonia’s courts have gone further, saying they will ask parties in legal proceedings to stop using .ru addresses for official communication, according to ERR.

How the Baltic states are hardening against Russia

Estonia's email quarantine forms part of a broader Baltic effort to limit Russian influence and strengthen defenses against military, cyber, and covert threats.

Estonia, Latvia, and Lithuania are constructing a Baltic Defense Line, a planned network of bunkers, anti-tank ditches, and other barriers, along their borders with Russia and Belarus. Latvia has also banned imports of Russian and Belarusian books, clothing, toys, and other goods.

The threat extends beyond cyberattacks: an Estonian court found that Russia’s military intelligence agency, the GRU, ordered the 2024 firebombing of a Ukrainian restaurant in Tallinn, part of a wider Russian sabotage campaign targeting European supporters of Ukraine.