PHP Email Not Working

I've recently installed my server on VPS, PHP mail is not working, I've tryed everywhere but I can't get it to work. If it is not a syntax error I would appreciate if someone could help with setting PHP mail up. Im running ubuntu 10.04

My code is:

     $ToEmail = 'my@email.com'; 

     $EmailSubject = 'Site contact form '; 
     $mailheader = "From: ".$_POST["email"]."\r\n"; 
     $mailheader .= "Reply-To: ".$_POST["email"]."\r\n开发者_StackOverflow中文版"; 
     $mailheader .= "Content-type: text/html; charset=iso-8859-1\r\n"; 
     $MESSAGE_BODY = "Name: ".$_POST["name"]."<br>"; 
     $MESSAGE_BODY .= "Email: ".$_POST["email"]."<br>"; 
     $MESSAGE_BODY .= "Message: ".nl2br($_POST["message"])."<br>"; 
     $MESSAGE_BODY .= "IP: ".$_SERVER['REMOTE_ADDR']";
     mail($ToEmail, $EmailSubject, $MESSAGE_BODY, $mailheader) or die ("Failure"); 

According to the log you posted:

Jun 13 11:49:42 hedgehog postfix/master[12617]: fatal: bind 0.0.0.0 port 25: Address already in use

This should give you a clue if you are unable to connect to your server.