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

[David Wilson]

You may be fighting the wrong problem.  Check the logs for Sendmail.
It is possible that the problem is somebody is dumping any packets with 
ECN (Explicit Congestion Notification) enabled.   The symptoms I have 
found for such ISPs is "we only support Windows".  There is a way to 
defeat ECN, but I generally don't go there.  A search on Google
will probably reveal the details. 
HTH,
Dave
-- 
David R. Wilson  WB4LHO
World Wide Network Services
Nashville, Tennessee USA	Need QSL cards?
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