problems with postfix

[Scott Kitterman]

On Fri, 30 Nov 2007 15:48:18 -0600 cesar <shortlyslot at yahoo.com.mx> wrote:
>
>The message that there receive those who send me emails to my server is
>the following one
>
>Hi. This is the qmail-send program at yahoo.com.
>I'm afraid I wasn't able to deliver your message to the following
> addresses.
>This is a permanent error; I've given up. Sorry it didn't work out.
>
><cesar.gomez at tecnoarteonline.com>:
>168.243.82.147 does not like recipient.
>Remote host said: 554 5.7.1 <cesar.gomez at tecnoarteonline.com>: Relay
> access denied
>Giving up on 168.243.82.147.
>

Please provide the output of postconf -n  and find what Postfix says about that message in 
/var/mail.log.

Scott K