Is my mail sending php code secure?
<?php
$newline = $_GET['message'];

$newline = str_replace("[N]","\n","$newline");
$newline = str_replace("[n]","\n","$newline");

mail($_GET['to'],$_GET['subject'],$newline,"From: ".$_GET['from']);

header( 'Location: http://site.com/report/report.html' ) ;
?>

This is the code I'm using to send a message to my corporate mail. the variables will be defined in my application. How safe is this?
Again, I uploaded some data via ftp to our server and added the link to that data to the message. How safe is this?
Is my mail sending php code secure?
===

<?php
$newline = $_GET['message'];

$newline = str_replace("[N]","\n","$newline");
$newline = str_replace("[n]","\n","$newline");

mail($_GET['to'],$_GET['subject'],$newline,"From: ".$_GET['from']);

header( 'Location: http://site.com/report/report.html' ) ;
?>

This is the code I'm using to send a message to my corporate mail. the variables will be defined in my application. How safe is this?
Again, I uploaded some data via ftp to our server and added the link to that data to the message. How safe is this?