A Tweet by Iowahawk included a link to this 2009 Tweet from Sonasoft. They are the company whose software is used by the Internal Revenue Service to back up emails on the IRS network.
If the IRS uses Sonasoft products to backup their servers why wouldn't you choose them to protect your severs? http://www.sonasoft.com
— Sonasoft.com (@Sonasoft) October 9, 2009
Sonasoft's slogan is "email archiving done right". I guess by right they mean according to the transparency standards of the Obama Administration. Either that or the software did properly back up Lois Lerner and her cohorts' emails and someone is lying about not being able to locate them.
If I were the CEO of Sonasoft, I'd be pushing the last explanation.