You can get pretty much the effect you want in practice by just delaying
the server greeting and/or the EHLO or HELO reply for long enough. (Much
less than the standard timeout.) Subdividing the reply and putting a delay
between the packets might help - you'd be detecting something similar to
a common bug in crappy web servers that require requests to arrive in a
single packet. However you don't need an extension to do it because it
doesn't affect correct clients and there's enough leeway in the existing
spec. Also, specifying an extension is a waste of time since it'll be
obsolete when the bad guys fix their code.
Tony.
--
f.a.n.finch <dot(_at_)dotat(_dot_)at> http://dotat.at/
FAEROES SOUTHEAST ICELAND: NORTHEAST 5 OR 6, OCCASIONALLY 7 IN FAEROES. SLIGHT
TO MODERATE, OCCASIONALLY ROUGH. OCCASIONAL RAIN. MODERATE OR GOOD.