[ic] Some emails can't be sent - could this be why ?

[David Wilson]

This might not be an Interchange issue at all.  I have found a number of 
clueless people are administering network hardware.  Particularly, some
ISPs are dumping any packets that have ECN  (Explicit Congestion 
Notification) enabled.  Those connections that are doing such things I
can't get traffic through, since I have been using ECN on many of my
boxes for a number of years.  It is possible to defeat it.  A search
on Google will probably give you some details.

BTW.  Some OSs don't implement it yet and they are not affected (those
written in Redmond).

FWIW,
Dave
-- 
David R. Wilson  WB4LHO
World Wide Network Services
Nashville, Tennessee USA	Need QSL cards?
david@wwns.com			http://store.wwns.com/lz1jz