Sendmail on RedHat 6.2

[Worapoj P.]

Dear all experist,

I would like your help. I got problem with Sendmail 8.9.3 on RedHat6.2 that included when installed OS. I want to use mailertable feature, I done configure as ,
===============================
remove comment on /etc/sendmail.cf as below,
#Mailer table (overriding domains)
Kmailertable hash -o /etc/mail/mailertable
then
edit /etc/mail/mailertable
add entry
delta.co.th smtp:detexvs01.delta.co.th
then
#makemap hash /etc/mail/mailetable
< /etc/mail/mailetable
do a testing
# sendmail -v worapoj@delta.co.th
orapoj@delta.co.th... delta.co.th: Name server timeout
worapoj@delta.co.th... Transient parse error

It wasn't direct mesg to smtp machine that I specified on /etc/mail/mailertable , it has always ask/query on DNS and finally failed.

Pls help
Many thanks
Worapoj
==> result

[Marco Paganini · Accepted solution]

Hello

When you add the line:

delta.co.th smtp:detexvs01.delta.co.th

To your mailertable file, you're telling sendmail to deliver all messages going to *@delta.co.th to detexvs01.delta.co.th. However, sendmail will deliver to the MX record referencing detexvs01.delta.co.th (not the A record). You probably have a MX record pointing back to the domain name.

In this case, change your line to:

delta.co.th smtp:[detexvs01.delta.co.th]

The square brackets tell sendmail NOT to use the MX record for the given address (probably what you want).

Regards,
Paga

[Worapoj P.]

Dear Marco
after chaned as you sugges, it still be problem persistant
===================================
[root@dettech /root]# sendmail -v worapoj@delta.co.th
TEST
.
worapoj@delta.co.th... delta.co.th: Name server timeout
worapoj@delta.co.th... Transient parse error -- message queued for future delivery
worapoj@delta.co.th... queued
[root@dettech /root]# mailq
Mail Queue (1 request)
--Q-ID-- --Size-- -----Q-Time----- ------------Sender/Recipient------------
LAA04359 7 Thu Dec 20 11:22 worapoj
(host map: lookup (delta.co.th): worapoj@delta.co.th
==========================================
it has always look for DNS

Best Reagrds,
Worapoj

[Marco Paganini]

Hello,

Hmmm. That's strange.
A few questions:

1) Can your server effectively resolve delta.co.ch? I mean, what happens if you do a

host delta.co.ch ?

Also, it seems that since all mail is being sent to that particular host, it's a good candidate to be the MX record for that domain (you won't even need the mailertable). Isn't that the case?

2) what is the result of:

sendmail -bv test@delta.co.ch ?

Regards,
Paga

[Worapoj P.]

Dear Marco
answer you
(1) i done i add "172.x.x.x delta.co.th" some question mailertable feature doesn't work with sendmail on Linux or not?
(2) #sendmail -bv worapoj@delta.co.th
worapoj@delta.co.th... deliverable: mailer smtp, host [detexvs01.delta.co.th],user worapoj@delta.co.th
but
from
#sendmail -v worapoj@delta.co.th
delta.co.th: Name server timeout
worapoj@delta.co.th... Transient parse error -- message queued for future delivery

but actually couldn't send as error text above.

pls suggest
worapoj

[Marco Paganini]

Hello,

It surely does! I've used it without any problems. One question: Where exactly are you putting your mailertable file? Also, please send me the output of:

dig delta.co.ch mx

Regards,
Paga

[Marco Paganini]

Hello again,

oops...

Just one more thing... Do a 'host delta.co.ch' and tell me the results. Sendmail MUST resolve the destination address even if it's not going to deliver to that address directly! Can you resolve 'delta.co.ch' ? (send me the output of the "host" command above).

Cheers,
Paga

[Worapoj P.]

Dear Paga
here are your request,
# dig delta.co.th

; <<>> DiG 8.2 <<>> delta.co.th
;; res options: init recurs defnam dnsrch
;; res_nsend to server default -- 0.0.0.0: Connection refused

# host delta.co.th
Host not found, try again.

note i haven't configured any DNS query(/etc/resolv.conf) and DNS server(named), just used simply host file

And entry on /etc/nsswicth as below,
#hosts: db files nisplus nis dns
hosts: files

Thank your very much for your help.
worapoj

[Marco Paganini]

Hello Worapoj,

Ah, now it looks like we found your problem.

Sendmail *really* wants to use DNS, even when you're just relaying email (dumb, isn't it?).

Well, you can tell it not to use DNS by editing your /etc/nsswitch.conf and changing the 'hosts' entry (you did that already) and re-generating a /etc/sendmail.cf based on a .mc file.

Add the following lines to your .mc file:

FEATURE(`accept_unresolvable_domains')dnl
FEATURE(`accept_unqualified_senders')dnl

Note that you will need M4 installed to do this job.

PS: You may also consider another MTA like exim.

Hope it helps,
Paga