[WBEL-users] problem acepting incoming mail

["Raúl D. Pittí Palma"]

Saludos!
I have configured a mail server that is working weird.
Whenever i try to send a mail to a local user, from the outside, i 
recieved the following message:

*********ERROR MESG. START*********
<TESTUSER@MYDOMAIN.COM>:
<SERVER IP ADRESS> does not like recipient.
Remote host said: 550 5.7.1 <TESTUSER@MYDOMAIN.COM>... Relaying denied
Giving up on <SERVER IP ADRESS>
*********end of error mesg.********

i am using sendmail, provided by whitebox.  I ahve the same 
configuration running on another server, but that one works just fine.
Any ideas ?
If someone want, i can send the sendmail.mc  file for revision...
Regards!
RP