🚀 go-pugleaf

Posting-Front-End: GNU Emacs 18.41.7 of Fri Aug 28 1987 on teknowledge-vaxc (berkeley-unix)


In article <20962@ucbvax.BERKELEY.EDU>, <honey@citi.umich.edu> writes:

    i suppose it's possible to make the local mailer a router that looks at
    the address and passes the message back to sendmail ... maybe not.

Yah... I've done it, sort of.  My hack (I call it "pathfinder")
doesn't pass the message "back to sendmail", though;  it passes the
message forwards, into another incarnation of sendmail, with a new
address.  I use "pathfinder" to locate the "best" path from my
machine (which is on the Internet) to arbitrary hosts on the UUCP
net, via one of about 15 different gateway systems.  Works pretty
well, in practice;  its biggest single drawback is that the message
passes through sendmail twice, thus generating two sets of syslog
entries.  Second biggest drawback is that only a single gateway is
selected for each message, and if that gateway's down, the message
sits in the local queue until it comes back up;  it's impossible to
reroute the message (e.g. by changing the topology files and rebuilding
the paths database) without manually removing it from the queue.

A better approach would be for the addressing lookup to occur within
sendmail, and for there to be several alternative paths (with costs)
for each destination host.  This would require more hacking with the
guts of sendmail's address-rewriting rules than I'm really comfortable
with, so I've deferred any such work until after the next appearance of
Comet Kohoutek.