As you may have heard, Karl does most of his e-mailing from an account maintained at the Republican National Committee. He has probably done so to evade a federal law that requires all White House records to be permanently preserved. (A law instituted in the wake of another flagrantly criminal Republican president, of course.) But we can leave that to one side for now...
Congressman Henry Waxman (D-CA), in his capacity as chairman of the House Committee on Oversight and Government Reform, had his people talk to the RNC's lawyer. The lawyer had some very interesting things to tell them.

In response to "unspecified legal inquiries" - which were almost certainly those of Patrick Fitzgerald in the course of his
convicting the Vice President's chief of staff on a felony charge of obstructing justice [just stop and think for a moment about the rank corruption entailed in that phrase] - in August 2004, the RNC suspended its policy of deleting e-mails after 30 days. However, despite this, White House staffers would still have been able to delete e-mails on their own.
The RNC now says that it does not have any of Karl Rove's e-mails from before 2005. It does not offer an explanation of what happened to the August-December 2004 e-mails. But it acknowledges the possibility that Rove could have deleted them.
Do you suppose he just thoughtfully wanted to lighten the burden on the RNC's storage capacity? Or - if we can stretch our imaginations to the very limit - was he just possibly trying to destroy evidence implicating him in the felony of exposing the identity of a CIA officer? That would be... what was that legal term again? Oh, right!
Obstruction of justice.
Oh, dear. Not a favorable climate for that sort of thing these days.

But wait! There's more!

At some point in 2005, the RNC started doing for Karl Rove something they did for absolutely no one else. They automatically archived his e-mails - making it impossible for him to delete them from the RNC server. They didn't want to say a whole lot about what made Karl so extra-special in this regard. But they acknowledged that the possibility of lawyers demanding to examine them someday had entered their minds.

Now as far as those August-December 2004 e-mails go: as any IT person can tell you, wiping out all traces of an e-mail is far from an easy thing to do. If Karl managed to pull it off, he must have been
very motivated.
And if he didn't, I think Waxman and Leahy are going to nail his fucking ass to the wall.
Better warm up that pardon pen, George! It's going to be getting quite a workout!
http://www.tpmmuckraker.com/archives/002998.php