It's lunacy to think that someone generated 160 MB of text as a fraud, and to date, nobody mentioned in the files has said "this particular e-mail is a fake." Or even tried to.

The second point is indisputable, and I've wondered if there'd been denials. I did some idle speculation on the very question of how you could produce a large-scale forgery, on the order of a typical email trove, ~160 MB. The answer is that you wouldn't try to create it from scratch. Instead, you'd "obtain" somebody's real email trove (logs + message files) and perform costmetic surgery on it. That way, you maintain the internal consistency between messages and headers and logs, sealing that source of forensic inquiry. Email is the easiest type of document to forge or alter, because it's plain text, sometimes inside HTML markup, and the only tool a forger needs is Notepad. Maintain the syntax and formatting conventions, use a "touch" program to preserve the file alteration timestamp, and alterations leave no technical fingerprints. Insert a few inflammatory phrases, alter some wording and word choices, fake just a tiny percentage of material, and in the end, you have a body of work whose mass alone argues for its veracity...as you just did. Even the authors of the emails might question their own recollections of what they wrote. See how easily it works? The size of it is not an absolute obstacle to performing the trick.

I don't personally know that that's what happened, 'course. The range of possible interpretations possible depending on whether your filter is benign or otherwise says that there's not enough information, and may never be unless we establish where the stuff came from.