A court in eastern Pakistan also slapped a fine of Rs 100,000 each on Shafqat Masih and his wife Shagufta Masih.
Additional District and Sessions Judge Amer Habib handed down the punishment yesterday to the couple, residents of Gojra of Toba Tek Singh (TTS) district of Punjab.
The verdict was pronounced at the district jail TTS, where the trial was held for eight months owing to security reasons.
Shafqat, 44, and his wife Shagufta sent a blasphemous text message insulting Prophet Muhammad, according to the FIR lodged against them on the complaints of cleric Malik Muhammad Hussain and a former Gojra tehsil bar president Anwar Mansoor Goraya.
"Although Shafqat confessed to have sent the objectionable message to the Muslims before the police because of fear of more torture but he and his wife denied the charges in the court," the couple's lawyer Nadim Hasan said.
He said the couple had been framed by the accused because of personal enmity. The couple would challenge the verdict in the High Court.