Perhaps the biggest scar on the governor’s tenure was the scandal known as Troopergate, which involved accusations that her administration improperly pressured the state’s top law enforcement official at the time, Walt Monegan, to fire a trooper, Mike Wooten, who had been in an ugly divorce with Ms. Palin’s sister. The governor later fired Mr. Monegan.

Even as one investigation found fault with Ms. Palin’s action in the case, she repeatedly insisted publicly that she had done nothing wrong. The e-mails show that she was even more emphatic in private exchanges with her closest staff.

“He can try to deflect from the reasons he was let go by blaming it on the Wooten issue, but he knows it’s not true and perhaps he doesn’t want a public discussion about his administrative skills being made public,” Ms. Palin wrote in July 2008 to several staff members from her Yahoo account.

In another note, she added, “Help me get the truth out” about “Walt’s stirred-up controversy.”

In still another e-mail, to her deputy press secretary, Ms. Palin attacked a string of what she said were false claims her former brother-in-law had made about her misusing a moose-hunting permit to deflect from her family’s accusations that he had illegally killed a moose. “Wooten has NEVER hunted with me,” Ms. Palin wrote, “and except for his illegal moose hunt in question he has never hunted moose or caribou with my family.”

While e-mails like these might fuel critics who question her policy acumen, others show Ms. Palin clearly engaged in lawmaking. She paid close attention to the legislative progress of what had been the top item on her 2006 campaign agenda, a plan for developing a natural gas pipeline.

“Even CP has admitted locking up tax rates for 30 years as Glenn suggests is unacceptable to the legislature, the Alaskan public, this administration and the Constitution,” she wrote, referring to the oil company Conoco Phillips. “They don’t even ask for a 30 year lock-up. He said that ‘the campaign’ didn’t have a problem with that fiscal certainty? Huh? And that he was the gas line consultant to the campaign? Huh?”

Ms. Palin’s regular combativeness could come across as pointless or noble. When she learned that Ben Stevens, the son of former Senator Ted Stevens and a former state Senate president, was still the state’s national Republican committeeman, Ms. Palin decided to call for his resignation. Ben Stevens was embroiled in a corruption investigation and Ms. Palin had built her statewide reputation, and her successful campaign for governor, on challenging Republican leaders she said were corrupt.