Use of free email accounts by those in the government, shunning official ones created by the National Informatics Centre (NIC), has sparked security concerns.
Junior officers, often the ones required to source sensitive data and information, routinely use popular email services.
An agriculture department official said district officials send him crop data - sensitive because it can move global markets - mostly from non-official accounts.
Sometimes, even those in top offices violate the rule.
Soon after the last month's Mumbai bombings, Prime Minister Manmohan Singh's staff used a Hotmail account to issue a statement.
The air force used an unofficial account to send out media releases on the recent $11 billion (Rs 49,500 crore) fighter jet deal.
The government, following advice from the home ministry, has now issued a directive that officials must only use official email accounts.
"The staffer in the PM's office exposed his address to servers on foreign shores where India's jurisdiction simply doesn't apply," said Pawan Duggal, a cyber law expert.
NIC chief BK Gairola did not respond to a query, but a secretary heading a government department denied such practices were rampant.
"I'm on a committee of inter-ministerial secretaries and all of us use official accounts only," he said, requesting anonymity.