If the IRS was using MS Exchange then her own hard drive is of no importance. Does anyone know if this was the case?
They were using this product, which is for backing up MS Exchange.
Plus this IRS document refers to Exchange - http://www.irs.gov/irm/part1/irm_01-010-003.html
Of course it also says backups are required and some records are federal records.
Are you starting from scratch? Even though IRS is using MS, they are claiming they never had an intention to back up all email. Pretty much left to the users to handle.
That’s their story.