MvdV> P4 was written with little or no concern for the situation
 MvdV> outside Z1 period.  For one it tacitly assumes local calls are
 MvdV> free. So it does not matter who calls who when it comes to the
 MvdV> host's obligation of delivering incoming routed mail. In Z2 local
 MvdV> calls are *not* free and so it does matter who calls who. That is
 MvdV> just one example, there are many others.

i beg to disagree... in the document known as P4, section 4.1 states 

"
A Network Coordinator has the following responsibilities:

   1) To receive incoming mail for nodes in the network, and arrange
   delivery to its recipients.
"

note the word "arrange"... seems that many skip over that words
and "assume" that that statement means that the NC's machine will
call the destination and send the message(s) to it... this is not so when
one includes that one, critical, word...

"arranging delivery" can include an arrangement whereby the
destination node calls the NC's system(s) and picks up any waiting netmail
headed to the destination system...

[ PS: apologies if this is an old thread... i've just a small bit of time
to try to catch up in a few echos... this is one of the first i'm skimming
over ;)  ]

)\/(ark