[JohnFen]

> I know personally several people who run mail relays and not only refuse to relay messages from and to Google email servers but even refuse to _receive_ emails addressed to their users from GMail addresses.

I don't refuse to relay messages to/from gmail addresses, but I do avoid interacting with gmail addresses as much as possible. The less I'm touching Google servers, the better.

Fortunately, most of the people I exchange email with don't use gmail.