PHP cannot find mail.php
From your error message, it would need to be in either ‘/usr/local/php5/lib/php’ which it can’t be as that is a system location. Or ‘/home/.marilee/sugars4life/sugars4life.com/skincare1/’.
If it is in that location, it is likely that the permissions are wrong on the file.
If it isn’t in that location, check for an .htaccess file somewhere and see if it is trying to change the PHP include settings. This will not work by default on DH as PHP is run as a CGI process rather than under mod_php. If this is the issue, post back as there are several ways around the issue.