sendmail configuration nightmare

[jprabaker]

Hi, I have an AIX system running 5300-12-05. I'm trying to set up sendmail to forward all mails to a mail-relay host and have the following defined in /etc/mail/sendmail.cf:

DS[xxx.xxx.xxx.xxx]

When I try to do a sendmail -v myaddress@mydomain.com I get:

mydomain.com: Name server timeout
kbaker@sccis.net... Transient parse error -- message queued for future delivery

After this, sendmail sends it to localhost.

I am fairly certain this is down to MX record lookup for mydomain failing. I've seen it before on Redhat and fixed it by creating the /etc/mail/service.switch and re-compiling the sendmail.mc file. This file told sendmail to ignore DNS and not try and look up the MX record. But this doesn't work on AIX and the problem still persists. I've got /etc/netsvc.conf set to "hosts = local,bind4" but this doesn't help either.

I'm guessing it's something really simple but it's completely escaping me and causing me to bang my head against a brick wall.

 

[w5000]

maybe your relay host does not work or is not reachable
have you tried to send some mail via the relay using simple smtp commands telneting on port relay 25?

 

[jprabaker]

Hi, thanks for the reply. Direct connection to the mail relay on port 25 works fine.

 

[iggsterman]

1. Please make sure the relay host resolves via DNS or put it in /etc/hosts. TEST that it is reachable by name. FQDN or a short name - does not matter.
2. Replace the DS in the format you specified, with:

[tt]DSmyrelayhost[/tt]

No brackets. "myrelayhost", of course needs to be the real one.

 

[iggsterman]

Does it work now?

 

[jprabaker]

Hi iggsterman, it turns out that some mails are working, others don't. Whatever I specify as the mailrelay DS value I can't get it to work for certain addresses, which leads me to believe that something is screwy with our DNS (knows about some external addresses but not others). If I can stop sendmail from performing a remote MX lookup and to just forward the mail to the relay I'll be fine. Is this possible on AIX? Changing the /etc/netsvc.conf file to state files then bind4 makes no difference, having a /etc/mail/service.switch doesn't work either.

 

[iggsterman]

Hmm. Your initial one should have worked actually. Another thing I would try is to use.
DS[fully-qualified_name_of_the_relay]
Make sure the name can resolve.
Restart the service of course.

 

[jprabaker]

Still banging my head with this one, I've tried defining the DS variable as follows:

DS[xxx.xxx.xxx.xxx]
DSmailrelay
DSmailrelay.domaim.com
DS[mailrelay.domaim.com]

Non of the above work and I've got several mails in the out queue that are deferred like so:

t5UAWJ8G16253030 0 Tue Jun 30 11:32 bakerj
(host map: lookup (btinternet.com): deferred)

Got an OS upgrade scheduled on our NIM server so will see if that makes a difference - can't see it through as I still think it's the DNS issue.

 

[iggsterman]

According to IBM

http://www-01.ibm.com/support/docview.wss?uid=isg3T1011217

the DS[relay] should work. In other words it should just forward everything that is sent out to the relay. If the DNS is broken the messages would queue up on the relay, not the sending host. I know it's silly to ask, but have you restarted the service? Also which sendmail do you use?