refused 'mail from' because return MX does not exist

Posted on 2004-09-22
Last Modified: 2012-06-21
I am getting this error only for emails sent from my Exch 2K server to users of a mail server in China:

There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            < #5.5.0 smtp;554 refused 'mail from' because return MX does not exist (#5.5.4)>

Here is the header of a failed email:

Microsoft Mail Internet Headers Version 2.0
Received: from ([]) by with Microsoft SMTPSVC(5.0.2195.6713);
       Mon, 20 Sep 2004 01:59:36 -0700
Received: from (localhost.localdomain [])
      by (8.12.10/8.12.9) with ESMTP id i8K9XTGZ013564
      for <>; Mon, 20 Sep 2004 02:33:29 -0700
Received: (from bugzilla@localhost)
      by (8.12.10/8.12.10/Submit) id i8K9XTeM013563;
      Mon, 20 Sep 2004 02:33:29 -0700
Date: Mon, 20 Sep 2004 02:33:29 -0700
Message-Id: <>
Subject: [Bug 534]  New: The expand field in the schedule remind display two "30" days...
X-Bugzilla-Reason: AssignedTo
X-OriginalArrivalTime: 20 Sep 2004 08:59:36.0514 (UTC) FILETIME=[277E3A20:01C49EF0]

Here is our setup. We have a Linux server, linuxbug, that runs a bug tracking program called Bugzilla. Bugzilla sends emails (relays) to a distribution list ( on our exchange server. Only recipients that have addresses ending in (our China site) get the error & the email is not delivered. If I send an email directly from the exchange server to a address it works fine. To work around this problem I have set up a rule in outlook to forward messages from to the people.

I am guessing my problem lies in one or both of the lines below from my email header:

Received: from (localhost.localdomain [])
Received: (from bugzilla@localhost)

I am also guessing that I will need to modify bugzilla or sendmail on my linux server to fix this. I am pretty new to linux so I want to make sure I am going down the right path....
Question by:gpietila
  • 5
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Expert Comment

ID: 12130064
Taking a look at your error I did an nslookup:
%nslookup -type=mx
Default Server:


*** can't find Non-existent host/domain

Non-authoritative answer:     preference = 10, mail exchanger =

Authoritative answers can be found from:     nameserver =     nameserver =     nameserver = dns1     nameserver =   internet address =

I would make your external DNS records for MX match the working site (or where ever you would like it to route)
Wait a while, and try them again (the dest. maybe cached)

Author Comment

ID: 12136928
Actually that nslookup should be for not

Expert Comment

ID: 12139441
You can edit the genericstable on your  sendmail box and have it map that outbound user to a different domainname.
what version of linux is it?

Author Comment

ID: 12147190
RedHat 9

I am pretty new to Linux, any instructions on how to edit the genericstable would be most appreciated.
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Author Comment

ID: 12162722
I found that WebAdmin allowed me to add a masquarading domain to Sendmail but I still get the original error. Do I need to stop and restart the sendmail service?

Expert Comment

ID: 12164047
Which version of linux are you using?

Author Comment

ID: 12165428
RedHat 9

Accepted Solution

h5uj earned 125 total points
ID: 12165486
you should have a file called /etc/mail/genericstable  if this file is not present do the following to find it
grep genericstable /etc/mail/
neil@hope:/etc> grep genericstable

it will look something like this:
Kgenerics hash -o /etc/mail/genericstable.db

edit this file ( /etc/mail/genericstable)  notice no .db on the end


***The <TAB> is the tab key***
from the unix prompt (as root) put
makemap hash /etc/mail/genericstable </etc/mail/genericstable

now any mail leaving this system matching bugzilla-daemon will be
and everyone else will be as they were before.

Author Comment

ID: 12218306
Unfortunately I am unable to work this issue any further. The company I work for ceased operations last week & I am out of a job.

I think h5uj was on the right track so I am going to give him/her the win. I wish I could actually try his suggestion..

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