[net.unix-wizards] Failed mail return addresses

lauren@rand-unix.arpa (12/06/85)

It should be pointed out that having extra X. file entries (like
the R line) in some recent uucp's doesn't necessarily do you too 
much good in real world situations.  There are several reasons for this.
The first is that any intermediate site (be it uucp-based or not) that does
not "understand" this additional information will drop it and the
additional return address info provided will vanish at this point.
But even if everyone ran the latest and greatest up to date software
at all times, much returned mail would still get lost.  And this
isn't UUCP's fault--it's the fault of our extremely hybridized
networking environment (I'm referring to the entire Internet).

Much of the problem is caused by gateways.  The various network
gateways (for DDN, UUCP, BITNET, etc.) are extremely variable in the
way they do address translations, frequently generating addresses
(in headers and in transmission envelopes) that will never work for
automatic replies.  Often these involve hybrid @, !, and % addresses
that even a net wizard would have difficulty in deciphering.  I'd say
that the vast majority of failed mail problems I've seen are the result
of gateway addressing problems, not the fault of any particular
"portion" of the networks themselves.  That is, it's not the fault of DDN
or UUCP or whatever, but more the fault of the interface and addressing
problems (still being resolved and implemented) between these nets.

--Lauren--