When i was doing some small mail campaigns for a forum i run, i noticed a lot of mail got trapped in the junkmail folder. This was the case with hotmail, yahoo, …
After searching for a solution i found a header modification of the mail message.
function SendYourMail($to,$from,$subject,$message){
$headers=””;
$headers .= “X-Sender: $mail \n”; //
$headers .=”From: $from [...]