Mancava una parentesi nel if.
Codice PHP:
<?php 
if(isset($_POST['title']) && isset($_POST['name'])  && isset($_POST['surname']) && isset($_POST['email'])  && isset($_POST['telephone']) && isset($_POST['fax']) )
 {  
$header="";  
$msg="";   
$boundary='--' . md5( uniqid(time()) );   
$ctencoding="8bit";   
$subject="Subject";   
$body="data";  
$to="xxx@gmail.com";   
$from=$_POST['email'];   
$fromname=$_POST['surname'];  
$ctype="application/octet-stream";   
$basename=$_FILES['all']['tmp_name'];   
$name=$_FILES['all']['name'];  
$header.="From: \"$fromname\" <$from>\nReturn-Path: $from\nX-Priority: 3\nTo: $to\n"; 
$header.="Mime-Version: 1.0\nContent-Type: multipart/mixed;  \n boundary=\"$boundary\"\n";   
$header.="Content-Transfer-Encoding: 8bit\n";  
$msg .="This is a multi-part message in MIME format.\n--$boundary\n"; 
$msg .= "Content-Type: text/plain; charset=iso-8859-1\n";  
$msg .= "Content-Transfer-Encoding: 8bit\n\n" . $body ."\n";  
$msg .="--$boundary\nContent-type: $ctype;\n name=\"$name\"\n";   
$msg .="Content-Transfer-Encoding: base64\nContent-Disposition: attachment\n filename=\"$name\"\n";   
$linesz= filesize( $basename)+1;   
$fp= fopen( $basename, 'r' );   
$content = chunk_split(base64_encode(fread( $fp, $linesz)));   
fclose($fp);   
$msg .= chr(13) . chr(10).$content;   
$result = @mail($to,$subject,$msg."\n",$header);   
if($result){  
echo "

Il tuo messaggio è stato inoltrato con successo!</p> 

Grazie!</p>";  }  
else{  
echo " 

E' stato riscontrato un errore sul server.
Impossibile inviare il messaggio.</p>

Riprova più tardi.</p>"; 
} 
}   else{ echo "

Non hai compilato tutti i campi del modulo!</p>

Campi mancanti:</p>";  
if(!isset($_POST['title'])){ echo "Title
";}   
if(!isset($_POST['name'])){ echo "Name
";} 
if(!isset($_POST['surname'])){  echo "Surname
";}   
if(!isset($_POST['email'])){ echo "Email
";}  
if(!isset($_POST['telephone'])){ echo "Telephone
";}  
if(!isset($_POST['fax'])){  echo "Fax
";} 
}  
?>
Se qualcosa non va puoi abilitare gli errori cosi
Codice PHP:
ini_set('error_reporting', E_ALL); 
ini_set("display_errors", 1);