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

Sun May 2 03:06:05 UTC 2010
Wang, Mary Y <mary.y.wang at boeing.com>

It's working now.  I just commented out some of the FEATURE lines in sendmail.mc file.
Mary


_____________________________________________
From:   Wang, Mary Y
Sent:   Saturday, May 01, 2010 6:21 PM
To:     'centos at centos.org'
Subject:        Sendmail Configuration Problem - 550 5.1.1 - User unknown Problem

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

Mary