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Old 06-05-2009, 11:29 AM   #1
jaguarfam
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Registered: Jun 2009
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sendmail error 550 - Host Unknown


Hi,
I'm new to Linux and need help on sendmail. We have a linux box where I have created some scripts. However, a functionality I need is to be able to send email using another smtp server.
my linux box address is 10.110.10.46 and my smtp server (windows) is 10.110.10.28

This is what I have in my sendmail.cf:
# "smart" relay host (may be null)
DS10.110.10.28

When I type the command
echo this is a test | /usr/sbin/sendmail me@mycompany.com

I get the error:
550 5.1.2 me@mycompany.com... Host Unknown (name server: 10.110.10.28: host not found)

I'm able to ping the server and the smtp server is setup to allow relays from this box

Any ideas?

Thank you for your help
 
Old 06-05-2009, 05:58 PM   #2
bathory
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You should put the IP address in square brackets
Code:
DS[10.110.10.28]
to avoid nslookups. If that doesn't work you should add an entry in /etc/hosts (or in your dns server, if you use one) for 10.110.10.28, so sendmail can resolve it.
 
Old 06-08-2009, 08:33 AM   #3
jaguarfam
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Registered: Jun 2009
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Smile sendmail error 550 - Host Unknown

Bathory,
Thanks for the suggestions. I had already put the IP in the /etc/hosts.

I found the solution. This is what happened:

When I read the Redhat documentation, it said that I needed to created the sendmail.cf in the /etc/mail folder. That's what I did. Apparently the changes I made never worked because the system was looking at the /etc/ folder and not /etc/mail folder for the sendmail.cf. So just to give it a try, I re-created the sendmail.cf in the /etc/ folder and it worked. The problem was then with the documentation.

Thanks again.
 
  


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