> The attacker spoofed the “From” field so it looked like the emails came from @google.com — something Google’s filters should have blocked outright. On iOS, Gmail doesn’t let you view full headers, so I had no way to double-check in the moment. Can somebody explain what exactly this means, and how it works?
Assuming I follow what you want to know, the wikipedia page on email spoofing should provide the info you desire. https://en.m.wikipedia.org/wiki/Email_spoofing I'm pretty surprised gmail didn't flag this at least. When I did it for a class in Uni, it always let me know that the FROM header didn't match the sender since that's a clear attack vector
I would also assume something as prominent as the Gmail website/app for iOS, and the google.com domain, would have all possible email security features correctly configured.
So.. is this not the case? Or is it, but due to bad UI, despite all this security, any schmoe can send email appearing to come from google.com, and I have to pore over unspecified details in the "full header" to spot a fake?