🚀 go-pugleaf

yes - rules.m4 not base.m4

There are a couple of minor differences between the flags for the ether
and tcp channel - the tcp channel is more suitable for transferring mail
on the internet (especially to IBM machines!).

However, it was also useful to add a little flexiblity so that you
can call yourselves one name to one set of machines (e.g. local hosts)
and one name to another set (e.g. the outside world, either on internet
directly or to some mail gateway machine on the ethernet that you have
no control over).  This was typically useful in the transition period
going to real domain names from the .arpa days.

-Jim.