Spam jumped 30 per cent during the month of March, according to security company Sybari.

The firm recorded 660,000 new spam outbreaks on 1 March and 883,000 on the 31 March. And more than one million new spam mails were sent on 25 March.

The company said each spam outbreak was made up of thousands and often millions of emails sent to inboxes around the world.

"Spam is a commercially driven phenomenon, so companies who use spam to promote their goods or services will lead into the holiday, just like many other suppliers, with intensified market awareness campaigns," said Sybari software's Julian Bogajski in a statement.

Sybari's Advanced Spam Defense technology measures the number of different spam attacks emitted in any one day by assigning a digital code to each email, rather than estimating the number of spam emails received in inboxes.