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sendmail relay server problem

apichart
Advisor

sendmail relay server problem

I'm getting a problem with relaying name server resolution. The "Chaoam03.com" acts as relay server.

1) In sendmail, the relay server is defined as
"DSchaoam03.com"
2) The output of "nslookup chaoam03.com" is
Name: chaoam03.com
Address: 10.20.2.31
3) when I try to run command "/usr/sbin/sendmail -v a@tca.com" I got the error "tca name server timeout". It seems the "tca" can not be resolved.

I can telnet to chaoam03.com on port 25 only. cannot ping. Does the connection to relay server must be fully reachable to do name resolution?
11 REPLIES
T G Manikandan
Honored Contributor

Re: sendmail relay server problem

YOu need to first check whether u are using a DNS for name resolution or the local hosts file.

T G Manikandan
Honored Contributor

Re: sendmail relay server problem

By default the sendmail looks for a nameserver and make sure that you have configured a name server for lookups
apichart
Advisor

Re: sendmail relay server problem

in nssswitch.conf, I have
hosts: files [NOTFOUND=continue] dns

in /etc/hosts,
192.168.9.120 abc xxx.com
10.20.2.31 chaoam03.com


no definition of tca.com.
T G Manikandan
Honored Contributor

Re: sendmail relay server problem

Yes,the problem is because of this,the sendmail looks for a default nameserver but you do not have one.

You will have to do some modifications in the sendmail.cf file to tell sendmail not to use DNS.

else you will have to use a DNS server for the lookups.

There is a good doc on the itrc ,check that out

http://www1.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000065255439
apichart
Advisor

Re: sendmail relay server problem

I did follow the document you kindly posted. I still get a problem when excuting the command.
#echo "Hi" | /usr/sbin/sendmail -v xxx@tac.com

xxx@tac.com... Connecting to chaoam03.com via relay...
220 chaoam03.comMicrosoft ESMTP MAIL Service, Version: 5.0.2195.5329 ready at Tue, 24 Aug 2004 14:04:21 +0700
>>> EHLO smsdtac.
501 5.5.4 Invalid Address
>>> HELO smsdtac.
501 5.5.4 Invalid Address


What doesn the error above mean?

Andrew Cowan
Honored Contributor

Re: sendmail relay server problem

This most likely means that the destination system does not have a valid DNS/host name for your machine. Try logging on to it from your system and run "who am i".
Joe White
Frequent Advisor

Re: sendmail relay server problem

Not sure from your last post if the system you're trying to get to is tca or tac. If your not using DNS I'd attempt to get the ip address for tca(or tac).com and add it to your hosts file. I'd then run a basic telnet to port 25 as follows;

telnet 25
HELO
MAIL FROM:root@chaom03.com
RCPT TO:root@tac(tca).com
DATA
This is a test
.
Quit
You'll know right away if you can talk to the system your attempting to reach and if it will relay mail.
Berlene Herren
Honored Contributor

Re: sendmail relay server problem

What is listed in your /etc/resolv.conf?

Try taking DNS out of the picture.

1. Rename /etc/resolv.conf

2. Your hosts line in /etc/nsswitch.conf should read

hosts: files

Place your relay in /etc/hosts file and make sure you can resolve it.

Test sendmail again.

Berlene
http://www.mindspring.com/~bkherren/dobes/index.htm
Jose Mosquera
Honored Contributor

Re: sendmail relay server problem

Hi,

Try the next trick. In your /etc/hosts file add the folloging line:
10.20.2.31 tca.com

The same procedure must be done for any external requested domain.

Rgds.

Re: sendmail relay server problem

I have seen this problem before.

Even though you edit nsswitch.conf, mail doesn't seem to get reconfigured.

Go into SAM, Networks and Communications, Name Service Switch, and configure hosts to the way you expect it.

Oh, when it prompts you to reboot, say No. It's not necessary.

When you bring up the name switch menu in SAM, it may look correct, but when you select "hosts", then go to configure, you may find it's looking up NIS first. Fix it, then all should be well.

alec pringle
Frequent Advisor

Re: sendmail relay server problem

I had the same problem with my sendmail configuration. I've just followed this thread and implemented the recommendation to check the settings in SAM and it magically started working - good tip!