gmail phishing warnings

[Michael_google gmail_Gersten]

I notice this "phishing" warning on every message from someone on a
gmail.com address, and only on messages from someone on a gmail.com
address.

I've regarded it as Google's being careful -- this is a message
originating from a non-google server, that claims to be from a google
user, but might actually not be. So, a warning to people that this
isn't actually sent from a google user.

And it's not. That it is a copy of what the google user sent off to a
list isn't the point; the actual message does come from someone that
is not the google user, and it claims to be from the google user. So
Google puts up a warning.