A New York court has sentenced a persistent spammer to 30 months in prison.

Adam Vitale, 27, sent 250,000 spam messages to more than 1.2 million email addresses belonging to AOL subscribers.

He and an accomplice, Todd Moeller, got around spam filters by changing email headers and using multiple computers.

"Spamming is serious criminal conduct. This is not a teenager engaging in child's play," US District Judge Denny Chin told Vitale.

Vitale, who had 22 previous convictions and had been investigated for running a prostitution ring via Craigslist, apologised and said he had learned his lesson.

He pleaded guilty to breaking anti-spam laws and received the 30-month sentence as well as a $180,000 fine to be paid to AOL.

The pair were caught in a sting operation by law enforcement officials who hired them to spam out messages promoting a new security product. The two agreed to do the job in exchange for half of the profits from sales.

Moeller was sentenced to 27 months for his part in the scam in November 2007.