How to Limit user to Sending Emails with Attachments

hi team is there any custom Shell script that will limit the user to send email with attachments we need to limit my email some user to send emails with Attachments, Like if some one send emails with attachments, systom should Discard the Attachments and send the to the Recipients. is there any options to filter outgoing emails particular domain in cpanel, this option only for some of the user in particular domain any shell script or Piping program to control this request, please advice