Among Lerner's surviving emails is one which shows her concern that a congressional investigation might discover evidence of IRS misconduct, if her messages were being saved.
http://www.foxnews.com/opinion/2014/07/11/irs-scandal-lois-lerners-perfe...
The Conservative Caucus is a public policy organization, contributions to which are not tax deductible. The IRS has determined TCC to be a 501(c)(4) organization, exempt from Federal income tax. TCC can receive corporate donations.