I have mixed feelings about this. > Not all affected email will necessarily be dangerous. To me, it sounds like they're saying that most of the "affected email" WILL be dangerous -- just not ALL of it -- and that's highly misleading, of course. Overall, though, I think this will be a good thing if it pushes more organizations ("mail senders") to implement opportunistic encryption for incoming mail and SPF/DKIM signin…
I have a plugin in Thunderbird that shows the DKIM status of incoming email as gray/red/green, meaning no DKIM/DKIM invalid/DKIM valid. Most of the email I get from business accounts (usually on Exchange), including those from the company I work at, have no DKIM. (Yes, I've complained to the ITsec dept. They don't even have SPF set up...) Of the rest, surprisingly many have invalid DKIM sigs.