Actually, the new probe system is pretty much a fully automated version
of this "Yale policy". On the other hand, there is an escape hatch for
people with problematic mail software, so it's a bit less radical (you
can use the CONFIRM command to stop the deletion process, but then you
have to do this with EVERY new probe so it ought to quickly reach a point
where people find the energy to bring up the issue with their mail
administrators).
Eric