deferred: connection timed out with NT

We recently installed a new release of SCO UNIX (5.0.6) and when I try to relay e-mail from the UNIX box to my NT server (the mail server) I get the following message from sendmail.

Deferred: Connection timed out with nt

I have nt set up as my relay server in sendmail.cf and the mail seems to be routed to the server but is not getting through.

Does this appear to be the result of a problem on my nt server?

Before the new release we had this no problems forwarding mail to the nt server and the names of the sending and receiving servers have not changed.

We will reboot the nt server in about 1/2 hour to see if that resolves the problem but I thought maybe this forum could help if there are some setup issues that I may need to check.

Thanks.

James

P.S. I really appreciate this forum thanks for all your help in the past and happy 2003.

Check that you have the correct IP address for the NT server in your host file and/or DNS. Make sure you can ping the server or trace the route for possible problems.

Then try connecting manually:

Example (from PCUNIX.com - SCO FAQ )

$ telnet mail.somewhere.com 25
Trying 192.168.75.194...
Connected to smtp.somewhere.com.
Escape character is '^]'.
220 smtp.somewhere.net ESMTP Sendmail 8.9.3+Sun/8.9.1; Thu, 12 Oct 2000 04:39:40 -0700 (PDT)

Once you have proven a good connection (enter quit to exit) you can relook at your sendmail for possible problems.

I went through the steps in the faq and was able to manually send an e-mail to my nt server.

Yet I still cannot e-mail using the mail command or sendmail it still gives the same error message.

thanks for your help

You can check sendmail by running it manually.

Send a message to a known user -

$ /usr/lib/sendmail -v knownuser@somewhere.com < /tmp/some.file

See where it hangs, check your messages file (or equiv) for errors.

You can also check your configuration by:
$ /usr/lib/sendmail -d0.1 -bt < /dev/null

Fix any errors it may show.

When I run sendmail in verbose mode it hangs when trying to connect to my nt box.

Once it gives up it comes back with the message "Deferred: Connection timed out with nt"

I later get an e-mail to my address on the unix box (the address I am sending from) telling me that the DNS lookup failed.

I think that I have set the IP for my Primary and Secondary DNS correctly in resolv.conf.

Still confused as to what the problem is.

Thanks for your help.

I used the info on ta 105706 at http://stage.caldera.com/ta/ to configure sendmail.cf and now e-mail seems to be working but it is rather slow to process (takes as much at 10 minutes to process).

Any ideas how I could speed it up?

Thanks.

What is the speed of your network? What else is running on your system and the NT system? How much mail (and sizes) are we talking about? Is DNS working correctly (this could be your problem since the timeouts when it can't find an address may slow you down or if the primary isn't working and it has to timeout and then hit the secondary).

Too many variables to give you a fix. Try doing an nslookup on a system you know should be in DNS. See how long it takes it to find it.

$ nslookup
Default Server: dns1.mydns.com
Address: 10.140.1.2

>
> knownserver

Insure it comes back quickly with the correct info (double check all the info on your NT server in DNS - PTR record too.).

After further review it appears that the direction I was given from our support staff was wrong.

What is happening is that the mail is being routed to our DNS and resolved through it to reach or nt server (hence the slowdown). The way the mail should work is that since the nt server is on the network and it's IP is in the hosts file I would think the mail program should just access the nt server and deliver the mail.

I may revert back to the sendmail.cf file before the changes from that ta document and try to getting it working from there.

What do you thinK?

Thanks

Sendmail is going to use DNS. I don't think you can or should get around this. If you set the sendmail.cf file to dump all email to the NT server, then it should not be going through the DNS servers (it will go there for the resolution of the A record and PTR but it will not actually send the email there).

To speed up the DNS lookups, start up a cache-only DNS server on your Sendmail server and put it's own IP at the top of the /etc/resolv.conf. This way everything stays local for DNS (after it gets the records it needs from the primary or secondary).

Using a caching only server should not be a problem with security, but you and your associates need to work that out.