This will be popcorn time for those using Gmail for business.<p>I have a plugin in Thunderbird that shows the DKIM status of incoming email as gray&#x2F;red&#x2F;green, meaning no DKIM&#x2F;DKIM invalid&#x2F;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&#x27;ve complained to the ITsec dept. They don&#x27;t even have SPF set up...) Of the rest, surprisingly many have invalid DKIM sigs.