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sendmail relay issue when dns forwarding turned off

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Peter A. Berger Jr.
Regular Advisor

sendmail relay issue when dns forwarding turned off

Cannot relay SMTP's from UX sendmail to Lotus Domino when the DNS (another machine) forwarding to the Internet is turned off. Want UX to just relay SMTP without name lookup.

Checked already:
ping notes01.us.ifm (Lotus Domino SMTP relay server).
nslookup notes01.us.ifm
telnet notes01.us.ifm 25
/sbin/init.d/sendmail stopped/started
/etc/hosts contains notes01.us.ifm, it also resolved via DNS when not in /etc/hosts.
/etc/mail/sendmail.cw has tons of local aliases for this machine. /etc/mail/sendmail.cf has DS notes01.us.ifm

Error output from sendmail -v -q:
hotmail.com: Name server timeout
email@hotmail.com Transient parse error -- message queues for delivery.

mailq error:
(host map: lookup (hotmail.com) : deffered
email@hotmail.com

When the windows DNS server has DNS forwarding turned on (which I cannot leave on) the SMTP's are sendmailed immediately. If forwarding is off the sendmails just sit there. Is there anything I can do to get UX to just relay the mail to Domino w/o name lookups and let Domino handle that?

Any help/411 would be great. Thanks.
6 REPLIES
Geoff Wild
Honored Contributor
Solution

Re: sendmail relay issue when dns forwarding turned off

In order to send email to the internet, you need to be able to resolve domains on the internet....

Why not add a DNS server to your resolv.conf file that is on the net - like maybe the providor of your Internet connection...or do you have an external DNS server for your Company's domain?

Rgds...Geoff
Proverbs 3:5,6 Trust in the Lord with all your heart and lean not on your own understanding; in all your ways acknowledge him, and he will make all your paths straight.
Berlene Herren
Honored Contributor

Re: sendmail relay issue when dns forwarding turned off

When you remove DNS, do you also change your nsswitch.conf to hosts: files? And also rename the resolv.conf?

Berlene
http://www.mindspring.com/~bkherren/dobes/index.htm
Peter A. Berger Jr.
Regular Advisor

Re: sendmail relay issue when dns forwarding turned off

I can try to point /etc/resolv.conf to Sprint's (ISP) DNS servers instead of our own internal-only DNS servers. I'll do that and post my results.

BTW: This UX machine utilizes the internal corporate DNS servers and not the /etc/hosts to resolve names.

Thanks for the tips.
RAC_1
Honored Contributor

Re: sendmail relay issue when dns forwarding turned off

Sendmail can use it own's file (/etc/mail/service.switch) for name service.
You can have different name service resolution setp for sendmail)

But I think with latest sendmail versions, it it no longer there. Check this option.

Anil
There is no substitute to HARDWORK
W.C. Epperson
Trusted Contributor

Re: sendmail relay issue when dns forwarding turned off

That should be
DSnotes01.us.ifm
and notes01.us.ifm must be resolvable.
"I have great faith in fools; self-confidence, my friends call it." --Poe
Peter A. Berger Jr.
Regular Advisor

Re: sendmail relay issue when dns forwarding turned off

I found the answer. I put my DMZ DNS server third in the list of name resolvers in /etc/resolv.conf. This DMZ DNS server does indeed resolve/talk to the Internet via Sprint ISP's authroitative DNS servers. The UX sendmail emails were sent to our internal SMTP Domino relay server immediately.

I did change the DS notes01.us.ifm to DSnotes01.us.ifm, but this didn't seem to make a difference.

The problem seems to be resolved. Thanks to y'all for your tips/suggestions.

-- Pete