php and mail

Hi: I have a short script that use in php to send email out acknowledging email and sending web generated notces. mail($to, $subject, $body,"From: $from \nContent-Type: text/html; charset=i so-8859-1 \n"); Recently we've set up a new server but php won't send mail generated by this script. We've checked our sendmail and everything else seems to work except for this script. In addition, it appears that any application we have on the server that relys on php is failing to send email as well. Does anyone have any suggestions Thanks Much Ron