Internal Server Error Premature end of script headers: /usr/local/cpanel/whostmgr/docroot/cgi/addon_mailscanner.cgi: Please check /usr/local/cpanel/logs/error_log for the exact errorThis is most likely happening because you updated cPanel to a new version but had not kept the MailScanner Front-End completely up to date. Manually reinstalling MSFE should fix it. Follow the instructions here: