If you want to block the access of autodiscover/autodiscover.xml then you can do this with some of directives. You have to modify the /usr/local/apache/conf/includes/post_virtualhost_global.conf file and add below code in this configuration file:
After adding code you can restart Apache.
Code:
Alias /htdocs_autodiscover /usr/local/cpanel/htdocs/
ErrorDocument 404 /htdocs_autodiscover/404.shtml
RedirectMatch 404 ^.*[a|A]utodiscover.xml$
Code:
/scripts/restartsrv_httpd –hard