> Please indicate some historical basis for moving an installed base of > users on this kind of scale and for this kind of reason. Times have changed. End users aren't the problem anymore. We have easy, if not automatic, updating for every major user environment. The critical point is the SMTP servers. I believe the great majority of them understand the spam pain, so they would be motivated to change. You throttle SMTP relative to the enhanced protocol to motivate the remaining good guys to convert, and as time goes on and only the bad guys are left, you throttle it even more. .swb