sendmail problems - "Name server timeout"

[Andres_13]

Hi all,

The sendmail service seems to be work incorrectly since i installed an oracle's 10g instance on my server (at least i guess that because before that it was working properly).

When i try:

#sendmail -v andres@mydomain.com

the following message appears:

andres@mydomain.com... mydomain.com: Name server timeout
andres@mydomain.com... Transient parse error -- message queued for future delivery
.
andres@mydomain.com... queued
#

The /etc/mail/sendmail.cf seems to be right (only DS is set to hostname.mydomain).

What i can do to solve this issue?

Thanks & Regards
Andres

[Sanjay_6]

Hi,

Is "hostname.mydomain" your smart relay ?.

If so, make sure your DNS resolution is working okay.

# nslookup hostname.mydomain

Hope this helps.

Regds

[Steven E. Protter · Accepted solution]

If you fix name resolution the mail will either go or be rejected.

Since you are using the DS directive in sendmail.cf make sure the server in that directive allows you to relay.

If not, check the name servers in /etc/resolv.conf and make sure they are giving you answers.

I use the IP address for DS relay because that lets me send mail even when the DNS servers are down.

DS
[192.168.0.4]

SEP

[Andres_13]

Ok,

-"hostname.mydomain" is my smart relay.
-i can resolve names from this machine over the LAN.
-My DNS resolution is OK.
-And i'm using IP adress for DS relay.

Any advice?

Thanks & Regards
Andres

[Steven E. Protter]

I would say look at the relay server.

It MUST allow relay from your server, preferably by IP address. If this does not get checked and verified all other efforts will fail.

SEP

[Andres_13]

Thanks for your response, Steven.

I double-checked this issue and it allows IP relay from my server.

I´m not sure what's wrong cause all seems to be OK.

Next step??

Thanks & Regards
Andr

[Steven E. Protter]

Test the relay

sendmail -v -d8.99 -d38.99 someone@outside.net

type some text

.


See results.

If you get the same error as before, check relay.

SEP

[Andres_13]

We did it!!

This problem was solved once i created the /etc/nsswitch.conf file and set
hosts: files

At this point sendmail attempt to "send a mail" whit "hostname." so i have to edit the /etc/hosts and set "hostname.mydomain.com"

And this solve the problem, but i'm curious about what really happen, which file "appends" the "mydomain.com" to the hostname, and why it works for a while and suddenly it not!

All assuming that i have another server on my lan with almost the same SW & HW configuration.

However it works now.

Thanks & Regards

[Andres_13]

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