An e-mail  message can not be delivered to a unix server

Posted on 2008-10-23
Last Modified: 2012-06-27
One of my users is trying to send an e-mail to the following domain"" in response we received the following error message "The message cannot be delivered due to a configuration error on the server. Please contact your Administrator.
            < #5.3.0 X-Unix; 73>
we don't use any unix servers in my company, we have an Exchange 2003 server and my user is using Outlook 2007 Pro. My question is "is the problem on my end or on the recipients end? if the problem is on my side how can I fix it?
I will aprreciate any suggestions.
Question by:Colombia1
  • 2
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Expert Comment

ID: 22790275
There may be an issue with your DNS.  It looks like may be blocking you as spam due to DNS. Go to and run the free domain health check. It will check to see if you have dns issues.  another site that does DNS checks is

Expert Comment

ID: 22790291
It looks like isnt free anymore try

Author Comment

ID: 22791288
Thanks for the comment. I went to, I ran the domain health check as you recommended and it passed all of them. It appears that I don't have any DNS issues. Do you have another suggestion?

Accepted Solution

Saranyakkali earned 500 total points
ID: 22797172
Yes, the problem not from your end..,  Unix server must allow incoming mails to users..  or unix mail server broken.
you can do bellow testing things,

1) ask them to send mail to you from unix server and reply to them. (command line you ll get proper details)
mailx -v -s "testing" youremail address

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Author Comment

ID: 22798752
Great, Thanks for your help.

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