Setting up sendmail to relay to exchange server

raymwu · 10-27-2010, 09:39 PM

newbie and first time poster tho am a HPUX guy - sorry, but at least trying to branch out...

Have read a whole bunch of threads from how and troubleshooting but still having problems.

Was thrown a box configured by someone who resigned today. Need to get mail from the box outbound via SMTP relay off our exchange server.

Had edited the existing sendmail.mc file's SMART_HOST definition to our smtp gateway (I can telnet to port 25 and talk to it) be:
/define(`SMART_HOST', `10.1.106.87')dnl

The resulting sendmail.cf failing the parse upon startup (there's a unknown configuration line "dn1 dn1" at line 63 which i have to manually delete and then sendmail starts up fine.

Sent a test mail and the maillog contains:

Oct 27 22:34:11 dmzweb01 sendmail[4266]: o9S2YBEe004266: from=root, size=34, class=0, nrcpts=1, msgid=<201010280234.o9S2YBEe004266@dmzweb01.mathesondirect.com>, relay=root@localhost
Oct 27 22:34:11 dmzweb01 sendmail[4267]: o9S2YBDF004267: from=<root@dmzweb01.mathesondirect.com>, size=355, class=0, nrcpts=1, msgid=<201010280234.o9S2YBEe004266@dmzweb01.mathesondirect.com>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Oct 27 22:34:11 dmzweb01 sendmail[4266]: o9S2YBEe004266: to=rwu@matheson-trigas.com, ctladdr=root (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=30034, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (o9S2YBDF004267 Message accepted for delivery)
Oct 27 22:36:11 dmzweb01 sendmail[4269]: o9S2YBDF004267: to=<rwu@matheson-trigas.com>, ctladdr=<root@dmzweb01.mathesondirect.com> (0/0), delay=00:02:00, xdelay=00:02:00, mailer=relay, pri=120355, relay=10.1.106.87. [67.215.65.132], dsn=4.0.0, stat=Deferred: Connection timed out with 10.1.106.87.

mailq shows:
/var/spool/mqueue (1 request)
-----Q-ID----- --Size-- -----Q-Time----- ------------Sender/Recipient-----------
o9S2YBDF004267 5 Wed Oct 27 22:34 <root@dmzweb01.mathesondirect.com>
(Deferred: Connection timed out with 10.1.106.87.)
<rwu@matheson-trigas.com>

Was thinking of starting from scratch and put back sendmail.mc.rpmnew but was hoping on something quicker?

Thanks for your help.

acid_kewpie · 10-28-2010, 02:40 AM

Well despite you saying you can telnet to that relay, it's saying otherwise. What I don't really understand is "relay=10.1.106.87. [67.215.65.132]" as, AFAIK, that says that's it's resolving the 10 IP address as a domain name to the 67 address. You might want to do something like run tcpdump to see what network traffic is actually occurring between these IP addresses.

feinbein · 10-28-2010, 03:47 AM

You said you could telnet to your relay and talk to it.
So does this:

Code:

telnet 10.1.106.87 25
.... answer from mail relay .....
helo dmzweb01.mathesondirect.com
mail from: root@dmzweb01.mathesondirect.com
rcpt to: <email test>@<something out>
data
mail test
.<hit return>

give you something like 'mail sent'?

Does your Exchangeserver also stand in the DMZ? You might want to tell the Exchangeserver to accept mails from dmzweb01 or the corresponding address for relaying. If the Exchangeserver is set up reasonably secure it want accept mails from just any host out of the box. I am just guessing here but I assume Exchange and dmzweb01 are NOT in the same subnet.
Otherwise, if your Exchangeserver is using a smarthost as well (which is a good idea), you might just use that same smarthost directly from dmzweb01.

Christian

raymwu · 10-29-2010, 09:21 AM

Thanks Chris/Christian for the prompt reply.

I'm actually perplexed by some other behavior that might be related. Despite having the mail relay, 10.1.106.87 in the hosts file as smtp.matheson-trigas.com, the hosts line in nsswitch.conf to be "files dns", nslookup can't succesfully find smtp.matheson-trigas.com as it is in the hosts files but resolves out to the public DNS server which has the public facing address of smtp.matheson-trigas.com.

I actually saved off the current sendmail.cf and sendmail.mc, copied in new ones from the .rpmnew templates, made a simple change in the mc file for smart_host to point to 10.1.106.87, generated a new sendmail.cf - tios time w/o the error of a bad line and see this is the maillog now (there's no longer callout to the 67 address:

Oct 29 09:15:06 dmzweb01 sendmail[19711]: o9TDF1wx019711: to=root, ctladdr=root (0/0), delay=00:00:05, xdelay=00:00:00, mailer=relay, pri=30828, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (o9TDF6q4019722 Message accepted for delivery)
Oct 29 09:15:06 dmzweb01 sendmail[19723]: o9TDF6q4019722: to=<root@dmzweb01.mathesondirect.com>, ctladdr=<root@dmzweb01.mathesondirect.com> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31379, dsn=2.0.0, stat=Sent
Oct 29 09:20:06 dmzweb01 sendmail[19751]: o9TDK1oM019751: from=root, size=828, class=0, nrcpts=1, msgid=<201010291320.o9TDK1oM019751@dmzweb01.mathesondirect.com>, relay=root@localhost
Oct 29 09:20:06 dmzweb01 sendmail[19765]: o9TDK6jR019765: from=<root@dmzweb01.mathesondirect.com>, size=1131, class=0, nrcpts=1, msgid=<201010291320.o9TDK1oM019751@dmzweb01.mathesondirect.com>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Oct 29 09:20:06 dmzweb01 sendmail[19751]: o9TDK1oM019751: to=root, ctladdr=root (0/0), delay=00:00:05, xdelay=00:00:00, mailer=relay, pri=30828, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (o9TDK6jR019765 Message accepted for delivery)
Oct 29 09:20:06 dmzweb01 sendmail[19766]: o9TDK6jR019765: to=<root@dmzweb01.mathesondirect.com>, ctladdr=<root@dmzweb01.mathesondirect.com> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31379, dsn=2.0.0, stat=Sent
Oct 29 09:25:06 dmzweb01 sendmail[19809]: o9TDP1pZ019809: from=root, size=828, class=0, nrcpts=1, msgid=<201010291325.o9TDP1pZ019809@dmzweb01.mathesondirect.com>, relay=root@localhost
Oct 29 09:25:06 dmzweb01 sendmail[19819]: o9TDP6dE019819: from=<root@dmzweb01.mathesondirect.com>, size=1131, class=0, nrcpts=1, msgid=<201010291325.o9TDP1pZ019809@dmzweb01.mathesondirect.com>, proto=ESMTP, daemon=MTA, relay=localhost.localdomain [127.0.0.1]
Oct 29 09:25:06 dmzweb01 sendmail[19809]: o9TDP1pZ019809: to=root, ctladdr=root (0/0), delay=00:00:05, xdelay=00:00:00, mailer=relay, pri=30828, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (o9TDP6dE019819 Message accepted for delivery)
Oct 29 09:25:06 dmzweb01 sendmail[19820]: o9TDP6dE019819: to=<root@dmzweb01.mathesondirect.com>, ctladdr=<root@dmzweb01.mathesondirect.com> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=31379, dsn=2.0.0, stat=Sent

raymwu · 10-29-2010, 09:28 AM

Here's the log of doing the email by hand. The smtp gateway is not in the DMZ along with this server and I have been assured by the Exchange people that they are set up to accept inbound requests from this box:

root@dmzweb01 ~]# telnet 10.1.106.87 25
Trying 10.1.106.87...
Connected to smtp.matheson-trigas.com (10.1.106.87).
Escape character is '^]'.
220 smtp.matheson-trigas.com Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at Fri, 29 Oct 2010 10:22:17 -0400
HELO
250 smtp.matheson-trigas.com Hello [206.18.165.79]
mail from: root@dmzweb01.mathesondirect.com
250 2.1.0 root@dmzweb01.mathesondirect.com....Sender OK
rcpt to: rwu@matheson-trigas.com
250 2.1.5 rwu@matheson-trigas.com
data
354 Start mail input; end with <CRLF>.<CRLF>
Test message from telnet
.
250 2.6.0 <EXCHANGE1NV10Bjpvrq00010b6e@smtp.matheson-trigas.com> Queued mail for delivery