The agency said that because of financial and computing restraints, some emails “that do not qualify as official records” had been stored only on individuals’ computers and not on servers, and that “backup tapes” from 2011 “no longer exist because they have been recycled.”
The I.R.S. went on to say that after May 2013 it changed its archival policy so that backup devices would no longer be recycled. It also said that it was not in contact with Ms. Lerner, who quit last September after serving as the head of the agency’s division on tax-exempt organizations, and could not interview her.