It's been nearly five years since former White House political adviser Karl Rove sent an incriminating email to then Deputy National Security Adviser Stephen Hadley indicating that Rove had a candid conversation with Time magazine reporter Matthew Cooper about covert CIA operative Valerie Plame Wilson, and her husband, former Ambassador Joseph Wilson, a critic of the Bush administration's prewar Iraq intelligence.

Rove had insisted publicly and privately that he was not the source for a story Cooper wrote that unmasked Plame's affiliation with the CIA in July 2003 nor, Rove said, was he the source who provided syndicated columnist Robert Novak with the same information for a column that was published a few days before Cooper's. The email Rove sent to Hadley on July 11, 2003, just three months before the start of a federal probe into the leak clearly contradicted Rove's account.

Questions about Rove's email to Hadley resurfaced after the government watchdog group Citizens for Responsibility and Ethics in Washington (CREW) revealed last April that thousands of emails Rove sent over a four-year period via an email account maintained by the Republican National Committee might have been destroyed. Many of the emails Rove sent using his RNC account pertained to White House business and the fact that it was not archived is said to be a violation of the Presidential Records Act.

Additionally, CREW said it conducted an investigation that discovered the White House lost as many as 10 million emails. The White House said in a court document that it erased backup tapes containing the email archives, some of which relate to a wide-range of administration scandals, including the role of White House officials in the Plame leak.

In late September 2003, three months after he told Hadley in an email that he spoke with Cooper, Rove and about 1,000 other White House staffers were ordered to turn over all email correspondence that contained references to Plame and Wilson to then White House counsel Alberto Gonzales when the leak of Plame's undercover status was referred to federal investigators.

But the Hadley email was never turned over to Gonzales during the early stages of the Plame investigation.

Robert Luskin, Rove's attorney, had long maintained that the email was never found during the initial search because the right "search words" weren't used. Some reporters and bloggers have opined the Rove/Hadley email did not turn up because Rove sent it using his Republican National Committee account. But according to a little known story published in The Washington Post in December 2005, Rove used his government account when he sent Hadley an email describing his conversation with Time's Matthew Cooper.

In an email exchange a couple of weeks ago requesting that he clarify his position, Luskin said he "speculated that the [Hadley] email was overlooked because of a gap in search terms, but I have no direct knowledge." That contradicts his previous statements to Newsweek in which Luskin stated unequivocally that the email was not found because the wrong search terms were used.

"Neither Mr. Rove nor I was involved in any manner in the collection of emails or other electronic documents in response to subpoenas from the Special Counsel [Patrick Fitzgerald]," Luskin said. "Mr. Fitzgerald's staff worked directly with the White House counsel and the IT folks from the White House. However, Mr. Fitzgerald did advise me that Mr. Rove had absolutely no responsibility for the oversight and that he has never regarded the failure to turn over the [Hadley] email as 'culpable' by anyone."

That statement, or at least part of it, does not appear to be entirely accurate. In a May 10, 2007, deposition before investigators working for the House Oversight and Government Reform Committee, Rove's former assistant, Susan Ralston, testified that during the leak investigation she and Rove were instructed "to go and do keyword searches based on the subpoena that we got, and search all of his folders for keywords." Ralston said during her deposition that there were "six or seven" subpoenas Rove received from Fitzgerald for documents in the Plame leak. Any documents that were found were turned over to Gonzales. Yet the email Rove sent to Hadley was never turned over to Fitzgerald.

Luskin would not provide a copy of that email, which has never been released publicly. He said the contents of the exchange have been "widely reported." Luskin added that he had no interest in providing either the Hadley email "or any other documents," including a copy of a letter Fitzgerald sent Luskin that purportedly cleared Rove of criminal exposure in the leak case, to me because of a story I reported two years ago that stated Rove was indicted by Fitzgerald. Luskin added that I "played a despicable role in circulating false allegations concerning an indictment of Mr. Rove and persisted with the story even after it was demonstrated to be false" and he, therefore, would not provide documentary evidence that could demonstrate his client's innocence.

Fair enough. But Luskin also refused to voluntarily provide Senator Patrick Leahy, the Democratic chairman of the Senate Judiciary Committee, with the Hadley email and other electronic messages that Rove and Luskin turned over to Fitzgerald. Last May, Leahy issued a subpoena to former Attorney General Alberto Gonzales for the documents.

The subpoena covered a wide range of emails Rove sent over four years, some of which related to congressional investigations into the firings of nine US attorneys two years ago that Rove is widely believed to have played a hands-on role in.

Gonzales never met Leahy's May 15, 2007 deadline to turn over the emails. So on May 24, 2007, Leahy wrote to Luskin asking if he would forfeit the emails to his committee Luskin and Rove turned over to Fitzgerald. Luskin politely refused, according to a copy of a June 4, 2007, letter he sent to Leahy, obtained by this reporter.

"As you are aware, Mr. Rove cooperated fully with the investigation by the Special Counsel, Patrick J. Fitzgerald, into the disclosure of the identity of a CIA employee. As part of that cooperation, in April 2004, Mr. Rove made available to Mr. Fitzgerald two personal computers, a Blackberry, and a computer furnished to Mr. Rove by the Republican National Committee," Luskin wrote. "Mr. Fitzgerald arranged for the FBI to image all of the data on these computers. Without any constraint by Mr. Rove, Mr. Fitzgerald reviewed all of this data and made and retained copies of any information relevant to his investigation. Because the computers also contained confidential personal information and attorney client communications, Mr. Fitzgerald returned to me for safekeeping the imaged copies made by the FBI."

"The electronic copies made by the FBI, which I retain in their sealed form, only contain information created before early April 2004, when the FBI made the copies," Luskin added. "I have reviewed the documents and testimony made publicly available by this and other congressional committees investigating the termination of the United States Attorneys. I am unaware of any evidence suggesting that Mr. Rove may have played any role whatsoever in this matter before April 2004. Accordingly, I have no reason to believe that the materials in my possession contain any information relevant to this Committee's inquiry."

So what happened? And why didn't investigators, who searched Rove's emails and computers during the early days of the leak probe, find a copy of the email Rove sent Hadley?

A fascinating new book provides some possible answers.

David Gewirtz, a former computer science professor, a former product management director for Symantec who also held the title of "Godfather" at Apple Computer, Inc., and has written more than 600 articles about email, is the author of "Where Have All the Emails Gone?," the definitive account about the circumstances that led to the loss of administration emails. A detective story that reads like a "Dummies" book for the technically challenged, "Where Have All The Emails Gone?" relied upon good old fashioned shoe-leather reporting to tell the story of the missing emails and using the public record in attempting to solve the mystery.

In an interview, Gewirtz said the one possibility that the Rove/Hadley email never surfaced was that it was sent during a time when the White House had switched its email over from Lotus Notes to Microsoft Exchange, an issue in and of itself the author finds suspicious. The Rove/Hadley email may have been lost during the transition to the new email system.

"Why did they migrate at this time? The country was getting ready for war," noted Gewirtz, who said he has been speaking with Senate and House staffers probing the loss of White House emails. "It doesn't make sense that you would want to yank out your communications structure when you're building up toward war. It's crucial for our government to have qualified communications at a critical juncture. It's just mind bogglingly questionable that the White House would change its communication structure at that time period. Why did they need to do it then? It certainly provides a lot of plausible deniability for when emails are scrutinized."

"Another plausible reason, and this is the conspiracy theory, if you yank out an email system there goes your compliance with the Presidential Records act and there's the 'my dog ate it' excuse," Gewirtz said. "There's really no net loss other than a PR loss."

Gewirtz said his biggest concern about the loss of White House emails is the national security implications.

"There's a separate server for political activity. The server is not located or managed by security experts," Gewirtz said. "Emails are sent by White House staffers using an unsecured server. Hundreds of millions of emails are sent through the open Internet. An email message sent by a low level political employee says where the president is traveling. That can be seen by anyone and can put the president at risk. It's something of a disturbing experience talking to Washington politicians. Technical issue takes a back seat based on what the political goal is. The potential loss through homeland security is pretty profound."

In addressing Luskin's explanation that the Hadley email did not turn up because the wrong search terms were used, Gewirtz said that it's a possibility, but a poor excuse for not locating an email.

"You can type search terms that should but won't pick things up directly," he said. "You can choose to spell something wrong. Especially if there is no record of what you are searching."

Congressman Henry Waxman, the Democratic chairman of the House Oversight and Government Reform Committee, has been trying to unravel these complicated technical issues for the past seven months. Last July, Waxman wrote Fitzgerald seeking "transcripts, reports, notes, and other documents relating to any interviews outside the presence of the grand jury of" Rove, Hadley, President Bush, Vice President Dick Cheney, and other former White House officials.

In addition to his search for documents and questions surrounding the Plame leak, Waxman is also investigating how the White House lost millions of emails and why steps were not taken to preserve the electronic messages earlier . . . His committee is scheduled to hold a hearing this morning on the matter.

Gewirtz says that if congressional investigators are serious about tracking down missing White House emails, particularly emails related to the US attorney purge, then they need to start looking in the right place.

"There is a vast amount of email that has gone through the Republican National Committee," Gewirtz said. "If they're looking for a smoking gun on the firing of US attorneys, then its most likely [White House officials who played a role in the dismissals] sent the emails through the RNC system and not the EOP [Executive Office of the President] system. Meanwhile, everyone is looking for emails on the EOP sever because it's sexier. I think they are looking in the wrong place. If I were a betting man, I would say it's in the RNC system."

Still, Waxman said in an interview at his office in late December that he is determined to get answers to some of the lingering questions about Rove's role in the Plame leak, why the Hadley email never turned up, and whether there is a direct connection between that and the loss of millions of White House emails.

In the first of two letters Waxman sent Attorney General Michael Mukasey in December, the congressman said, "Fitzgerald and his staff have cooperated with the Committee’s investigation and have produced a number of responsive documents to the Committee. Among the documents that Mr. Fitzgerald has produced to the Committee are 'FBI 302 reports' of interviews with CIA and State Department officials and other individuals. Unfortunately, the White House has been blocking Mr. Fitzgerald from providing key documents to the Committee."

I met with Waxman in late December during an interview conducted by Truthout Executive Director Marc Ash at Waxman's West Los Angeles office. Waxman said two of the key documents his staff had been trying to obtain were a copy of the letter Fitzgerald sent to Luskin that apparently indicated that Rove was no longer under investigation, as well as the email Rove sent to Hadley. At the time of our meeting, Waxman had already sent Mukasey a second letter because the attorney general never responded to his first request. Waxman set a deadline of January 8 for the Plame investigation documents to be turned over to his committee.