i'm not 100% sure what you want, but maybe this will help:
it's possible to specify additional headers as the 4th argument of the mail() function. specify a nice 'From:' and your server won't feel the need to put in his own name...
Example:
$to = "eklee_at_skali_dot_com";
$subject = "how to hide server address when sending mail with php";
$body = "that's the way you do it!";
$headers = "From: \"Phil\" <me@phillipoertel.com>";
mail($to,$subject,$body,$headers);
look at the message source of any email to learn about other useful headers, for example Content-Type:text/html to send html mail.
hope this helps.
all of this can be found in detail @ http://www.php.net/mail .
phil!