It could be that the number is just an estimate. Perhaps the IRS looked at how many emails Lerner sent in a typical month from the time period they do have, and extrapolated over the missing time period? That would produce a number that's better than a wild guess, but wouldn't really tell us anything for sure.
It's possible they have more information than that. It's possible that the server logs from that time period have been preserved. It's been long enough since I admined an Exchange server that I don't remember what would be logged, exactly, but most email servers do maintain traffic logs with metadata information. If the IRS has email server logs which they used to estimate the number of emails Lerner sent and received, it would be worth asking them to produce the whole log in the hopes of obtaining a list of people she was corresponding with.
It's worth asking them how they came up with that number.
This entry was published Tue Jul 29 10:44:34 CDT 2014 by TriggerFinger
and last updated 2014-07-26 22:12:06.0.