Ted, you are ascribing more concern about this by the providers than I'm seeing.
Having talked to many of the same people at large mail providers that Dave has, and also done some policy work for more than one of them* I have to agree. Google has on the order of a billion mail users, and the other large providers have hundreds of millions. The idea that they would weigh those users against at most a few thousand people doing Linux or the IETF just isn't plausible.
R's, John * - expert witness stuff