Why the mail error for domains I don't host?

[Blake Swensen]

sendmail[93922]: j1L2kZa5093920: SYSERR(root): mx1.distinguish.com. 
config error: mail loops back to me (MX problem?)

I know everyone has seen this message at least once in their life from 
improperly configured sendmail.  However, my log is filling up with 
these messages for domains I do not host.... and when I dig the 
mentioned host, it always resolves to localhost (127.0.0.1).  This 
happens over and over again on for domain after domain.  Are there 
really that many unskilled admins who publish their mail server's 
address as localhost, or is this some sort of hack that I should worry 
about?

Blake

-- 
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The Internet Rescue Company - http://www.pyramus.com
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Blake R. Swensen         Pyramus Online, Inc.
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"We measure success by the success of our clients"