Faisal Shahzad, a Pakistani-born naturalized U.S. citizen, sent the e-mail to a large group of recipients in 2006, CNN reported Monday.
"Everyone knows the current situation of Muslim World," he wrote. "Everyone knows how the Muslim country bows down to pressure from the west. Everyone knows the kind of humiliation we are faced with around the globe."
"Can you tell me a way to save the oppressed?" Shahzad asked. "And a way to fight back when rockets are fired at us and Muslim blood flows?"
When he sent the e-mail, Shahzad had been in the United States for six years and was working in Connecticut as a financial analyst, CNN said.
There have been reports Shahzad has admitted the bombing attempt and said he had received training in Pakistan.
U.S. Attorney General Eric Holder has said Shahzad was working with the Pakistani Taliban.