malc@unrvax.unr.edu (Malcolm L. Carlock) (01/19/90)
I've got one fairly generic .cf file that I've successfully installed (with
a few modifications, such as addition of a tty mailer, different flags to
uux, etc.) on a number of machines here, including Suns (3.5 and 4.0.X) and
HP's (HP/UX). On all these machines, mail to locally known hosts (E and V
classes), as well as forwarding to designated Internet and UUCP relays, seems
to work just fine.
I've recently tried porting these same files to a couple of Ultrix systems
(V1.2 with no name server, and V2.1 with name server), and an old Symmetric
running 4.2-compatible Unix. On the V1.2 Ultrix system and the Symmetric,
when I try sending mail to any local host (those in the E class), I get a
message like the following:
user@local_host... Connecting to local_host.unr.edu.tcpld...
user@local_host... Host unknown
where 'local_host' is indeed a local host, noted as both 'local_host' and
'local_host.unr.edu' in the /etc/hosts files on these machines.
When trying to mail to a foreign host (one not in the E class or in /etc/hosts)
from these machines, I get a message like:
user@foreign_host... Connecting to internet_relay.unr.edu.tcpld...
user@foreign_host... Host unknown
It seems that sendmail is able to tell whether a host is 'known locally' or
not, but at some point decides it doesn't know about the host after all and
drops the mail. For foreign hosts, sendmail seems to know that the mail
should be forwarded to the designated internet relay, but doesn't seem to
be able to completely 'let go' of the mail and let the relay handle it.
"I don't know who this host is, so I ain't lettin' the mail out o' here!"
In these examples, all hosts that are in the E class are also in the
/etc/hosts file of the sending machine.
The V1.2 Ultrix machine came with a 'generic' sendmail.cf file, where you
alter a few lines to customize it to your own site. I get the same results
with the customized Ultrix generic file as with my own. The Symmetric has an
old, more or less home-grown sendmail.cf file which works, but forwards ALL
mail through the internet relay. I suppose I could try porting this to the
Ultrix machines, but I'd like to know first what's causing the problem...
Things are slightly better on the V2.1 Ultrix machine (the one with the
name server), but not much. Using the exact same base 'generic' sendmail.cf
file as on the 1.2 Ultrix machine, mail to local hosts is delivered with no
problems. However, an attempt to mail to a foreign host produces the same
message:
user@foreign_host... Connecting to internet_relay.unr.edu.tcpld...
user@foreign_host... Host unknown
I get the same kinds of results on these machine whether I tweak things to use
the tcp, tcpld, or uucp mailers.
My own generic file works on various Suns running both with and without name
servers and/or Yellow Pages, under HP/UX with no name server, and on a PDP-11
running 2.11 BSD, at the end of a UUCP link. On these Ultrix machines and
on the Symmetric, however, I get the results described above. Anyone know
what's going on here?
Thanks in advance,
Malcolm L. Carlock Internet: malc@unrvax.unr.edu
UUCP: uunet!unrvax!malc