The email, released by a House committee investigating the IRS, seems to counter Democrats' arguments that tea party groups weren't specifically targeted.
"Tea Party Matter very dangerous," Ms. Lerner said in the 2011 email, saying that those applications could end up being the "vehicle to go to court" to get more clarity on a 2010 Supreme Court ruling on campaign finance rules.
In another email, from 2012, Ms. Lerner acknowledges that the agency's handling of the tax-exempt applications had been bungled at the beginning, though she said they had taken steps to correct it.
"It is what it is," she said in the email, released Thursday by the Ways and Means Committee. "Although the original story isn't as pretty as we'd like, once we learned this [sic.] were off track, we have done what we can to change the process, better educate our staff and move the cases. So, we will get dinged, but we took steps before the 'dinging' to make things better and we have written procedures."
That email suggests agency employees knew they had gone overboard in their scrutiny — despite top IRS officials telling Congress that there wasn't any special scrutiny of conservative groups.
In another 2012 email, Ms. Lerner seemed to take sides in a battle between the Federal Election Commission and conservative group tax-exempt groups that were engaging in politics, saying that "perhaps the FEC will save the day."
Ms. Lerner has been removed from her post at the helm of the tax-exempt organizations division, but has not been fired from the IRS.
She asserted her Fifth Amendment right against self-incrimination in refusing to testify to the House oversight committee earlier this year, though committee members argue that she may actually have waived that right and should be recalled and forced to answer questions.
In releasing the latest emails, Ways and Means Committee Chairman Dave Camp said they show a dangerous patter.
"There is increasing and overwhelming evidence that Lois Lerner and high-level IRS employees in Washington were abusing their power to prevent conservative groups from organizing and carrying out their missions," he said. "There are still mountains of documents to go through, but it is clear the IRS is out of control and there will be consequences."
But Sander Levin, the ranking Democrat on the committee, said there is still no evidence that the IRS was driven by a political motive to stifle conservative views.
"Lois Lerner was incompetent in her management of the IRS tax-exempt division and unprofessional in her conduct — reasons why I immediately called for her to be relieved of her duties," Mr. Levin said.
He said, though, that the GOP is overselling what it's found during its investigation.
"Selective leaking by Republicans does not change the fact that tens of thousands of documents and dozens of interviews with IRS employees have revealed absolutely no evidence of political motivation, no evidence of outside influence and no evidence of White House involvement," Mr. Levin said.