[CentOS] Sendmail problem

Hello,

I am having a problem with returned mail.  I don't have something configured
correctly.

I have 6 virtual hosts on one machine and mail sent from these host is being
returned.  This is the transcript:

The original message was received at Tue, 11 Apr 2006 07:30:19 -0400 from
localhost.localdomain [127.0.0.1]

   ----- The following addresses had permanent fatal errors -----
<f5loar at charter.net>
    (reason: 553 #5.1.8 Domain of sender address
<apache at localhost.localdomain> does not resolve)

   ----- Transcript of session follows ----- ... while talking to
mail.charter.net.:
>>> MAIL From:<apache at localhost.localdomain> SIZE=1618
<<< 553 #5.1.8 Domain of sender address <apache at localhost.localdomain> does
not resolve
501 5.6.0 Data format error

I think this has something to with outgoing address mappings but not sure
how to fix it.  All virtual hosts are included in the local domains file.

TIA