[CentOS] Sendmail Configuration Problem - 550 5.1.1 - User unknown Problem

Sun May 2 02:00:47 UTC 2010
Les Mikesell <lesmikesell at gmail.com>

Wang, Mary Y wrote:
> Hi,
> I'm having this Sendmail configuration problem and stuck.  I've been doing googling/reading posts and none of the solutions matched my problem.
> I'm doing some testing, and have been getting this 550 5.1.1 ....User unknown error when I send the email to my company's email address.   When I send it to an external email address, such as yahoo, the message delivered successfully.  Of course, I'm doing the configuration behind a firewall.   I'm using a relay too, and I did declare the relay host in 'SMART_HOST' in the sendmail.mc file and have also recompiled it to produce the sendmail.cf.  I also restarted the sendmail service.
> ----------------------------------------------------------------------------------------------------------------------------------------------------
> telnet ana.boeing.com 25
> Trying 134.51.151.114...
> Connected to ana.boeing.com (134.51.151.114).
> Escape character is '^]'.
> 220 ana.boeing.com ESMTP Sendmail 8.12.11.20060308/8.12.11; Sat, 1 May 2010 16:39:06 -0700
> helo ana.boeing.com
> 250 ana.boeing.com Hello ana.boeing.com [134.51.151.114], pleased to meet you
> mail from:root at ana.boeing.com
> 250 2.1.0 root at ana.boeing.com... Sender ok
> rcpt to:mary.y.wang at boeing.com
> 550 5.1.1 mary.y.wang at boeing.com... User unknown
> 
> Any ideas?  I'm running on Sendmail 8.12.11
> 

Is ana.boeing.com your machine, the relay, or the target MX receiver?  Whatever 
it is, it thinks it should be able to deliver mail to boeing.com locally, but 
doesn't have a mary.y.wang user or alias.

-- 
   Les Mikesell
    lesmikesell at gmail.com