[Techtalk] sendmail config questions
wheelers at eskimo.com
Sat Aug 9 01:50:34 EST 2003
On Sat, 9 Aug 2003, Rudy L. Zijlstra wrote:
> Dennis Wheeler wrote:
> >I've got a remote server running RH 7.1 and sendmail 8.9 (I think)
> Hmmm, upgrade to the latest version (8.12.9 last i looked), it has
> several security fixes. As far as i know 7.1 is *old* and i have no clue
> whether RH is still bringing out patches for it. You may have to install
> from source. I have to admit i do not track RH (do not use them).
We'll eventually upgrade, but that'll require a plane trip. I'd like to
just get them up and running again first.
> >I suspect it might be an open relay, so I need to 1) turn that off if
> >it is and 2) verfiy that's it's not afterwards.
> This is default off on the later releases. You have to explicitly enable
> it to get an open relay with those
That's what I thought, but I wasn't sure how to verify it to be one way or
> >It is accepting messages now, but they are just being queued and not
> >delivered. They are running an exchange server that their clients are
> >accessing via pop (again, I'm not sure here), but I don't see where the
> >mail is being forwarded from the linux server to the nt server.
> Does it have a direct connection to the internet, or should it forward
> mail to the exchange server?
It's behind a firewall, but it is accepting connections to port 25
The logs show incoming messages, but they are being queued. It should
forward them to the exchange server.
I did try just now telneting to port 25 on the exchange server and sending
mail to a local mailbox. The exchange server seems to be queueing them as
well -- I'll be asking the NT admin about that in the morning.
> >And their internal domain name is different from their external domain
> >name. I tried sending a test message and eventually got an warning
> >response "Could not send for 4 hours", with a name sever timeout error, so
> >I'm suspecting this domain name difference may be the problem. They're
> Not likely. Most probably a nameserver misconfiguration on the redhat
> install. When sendmail has no dependable DNS access, it cannot deliver mail.
resolv.conf points to the internal dns (running on nt) as primary, and the
isp's dns as secondary
The problem I see is that the isp's dns only knows abcd.ext.st.us (not
real btw) and the internal dns only knows abcd.edu
> >running an internal DNS on the same nt server as their exchange server, so
> >I don't quite know how to query and/or modify it remotely
> >I'm currently reading RedHat's sendmail howto and lots of stuff on
> >sendmail.org. But there's so much, I'm getting lost.
> >I'd appreciate some suggestions.
> You likely need to tell sendmail to accept mail from both domain names.
> I cannot tell more without knowing more about the setup.
Is that in the sendmail config? or the MX records in the DNS? or both?
Thanks so much for your help so far.
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