Secure Mail Form using PHP

This issue has probably been discussed more than I've been able to find in the archive, so I'm sorry if I'm going over old ground. I'm trying to make sure my email form cannot be used for spam or injecting additional code and addresses in any way. So far I'm able to remove bcc, cc, to, etc but unable to remove \n & \r. If I could do that I'd consider it fairly secure. As you'll see below, I've been trying various ways of doing it. <snip> // CHECK FOR SPAM ATTEMPTS AND REMOVE THEM $Email = stripslashes($Email); $Senders_Name = stripslashes($Senders_Name); $Message = stripslashes($Message); $recipient = stripslashes($recipient); $subject = stripslashes($subject); $Email = preg_replace( "/[\n\r]+/", " ", $Email ); // Remove injected headers $find = array("/bcc\:/i","/Content\-Type\:/i","/cc\:/i","/to\:/i"); $Email = preg_replace($find, "", $Email); $Senders_Name = preg_replace($find, "", $Senders_Name); $Message = preg_replace($find, "", $Message); $recipient = preg_replace($find, "", $recipient); // $message = preg_replace($find, "", message); // $email=str_replace("\r","\n",$email); // $name=str_replace("\r","\n",$name); // $message=str_replace("\r","\n",$message); // $phone=str_replace("\r","\n",$phone); // $Email = ereg_replace( "\r", " ", $Email ); THIS DOES NOT WORK // $Email = ereg_replace( "\n", " ", $Email ); THIS DOES NOT WORK // $Email = ereg_replace( "bcc:", " ", $Email ); // $Email = ereg_replace( "cc:", " ", $Email ); $Senders_Name = preg_replace( "/[\n\r]+/", " ", $Senders_Name ); $Message = preg_replace( "/[\n\r]+/", " ", $Message ); $recipient = preg_replace( "/[\n\r]+/", " ", $recipient ); $subject = preg_replace( "/[\n\r]+/", " ", $subject ); </snip> <snip> // NOW SEND THE EMAIL mail("$recipient", "$subject.", $Message, "From: $Email ($Senders_Name)\nReply-To: $Email\n Sent by: $Senders_Name Email Address: $Email"); </snip> Thanks for any guidance.... Martin