Mohammed Taha had reportedly angered radical Islamists in Sudan after reprinting an unflattering article on the family of the Prophet Muhammad in 2005.
Publication of his newspaper was subsequently suspended for three months by the Sudanese authorities.
In his defence, Taha said it had been a misunderstanding and he was released, despite street demonstrations and calls for his death.
Taha had also angered several rebel groups in Darfur after articles condemning their actions were published in his newspaper.
Kamal Omer, a leading member of the defence team, said that the men would appeal their sentences.
"This is a police state, that is why we have this backwards, incorrect ruling," he said.
Omer had himself been imprisoned overnight for making public comments that his clients had been tortured to extract their confessions, Reuters reported.
Amnesty International had expressed concern at the time of the men's arrest that they could be tortured.