A man who hacked into Sarah Palin's e-mail during the 2008 presidential campaign was sentenced today to a year and a day, with the judge recommending a halfway house instead of prison.

US District Judge Thomas W Phillips also said David Kernell, 22, should get mental health treatment, based on defence comments today that he has had conditions including depression since he was 11.

Kernell hugged family members and friends after hearing the sentence. He declined comment as they left the courthouse with his attorney.

He was an economics major at the University of Tennessee when he deduced the answers to security questions and read e-mail in Palin's private account.

The Republican former vice presidential candidate and her daughter Bristol testified at the trial in late April that the hacking, followed by Kernell's online bragging and providing the password and Palin family telephone numbers to others, caused them emotional hardship. Palin previously declined comment about Kernell's sentence and said it should be up to the judge.

The prosecutors' pre-sentence filings said Kernell, a Democratic legislator's son, had posted online that he found "nothing that would derail her campaign as I had hoped, all I saw was personal stuff, some clerical stuff from when she was governor... And pictures of her family ... I read everything, every little Blackberry confirmation ... all the pictures, and there was nothing..."

The judge rejected a recommendation by prosecutors that Kernell be sent to prison for 18 months.

Kernell will not start the sentence until the Bureau of Prisons decides the location of his confinement, probably in about 45 days.

"They usually take the recommendation but they are not required to," the judge said.

Kernell, smiling at times after the sentence was announced, spoke during the hearing and apologised.