A US judge has handed down a jail sentence to a US spammer recommending that he stay behind bars for nine years.

Jeremy Jaynes, 30, one half of a sibling spam duo, was convicted under Virginia state law which forbids sending bulk emails using fake addresses.

He was found guilty of sending hundreds of thousands of spam messages to AOL subscribers, and was described by prosecutors as "the equivalent of snake oil salesmen".

It is believed that with the help of his sister, Jessica DeGroot, 28, who was fined $7,500, the duo pedalled non-existent products via email such as a 'FedEx refund processor' that supposedly allowed people to earn $75 an hour while working from home.

This allowed the siblings, both based in Raleigh, North Carolina, to amass a fortune of $24m. "This was just a case of fraud," said state prosecutor Samuel Fishel.

Jamie Cowper, senior technology consultant and anti-spam expert at messaging specialist Mirapoint, said that the punishment ought to fit the crime.

"While there may be an outcry in some quarters over a sentence of nine years for spam, this recommendation needs to be seen in context," he said.

"[They] have defrauded thousands of people to the tune of $24m, hardly an insignificant amount of money. Plain and simple, this man is a serial criminal preying on susceptible individuals using the internet in good faith.

"We are happy to hand down hefty sentences to con artists that dupe OAPs through more 'traditional' methods of deception. Why should Jaynes be treated any differently?"