Email is not working

Hi,
I am creating a website with your theme in which email is not working. While submitting any data ajax spinner is rounding for an unlimited time.

On debugging, also getting this error:

Notice: Only variables should be passed by reference in /home/hblsadmin/domains/hblsgindia.org/public_html/wp-content/plugins/redux-framework/redux-core/inc/classes/class-redux-functions-ex.php on line 311

Notice: Only variables should be passed by reference in /home/hblsadmin/domains/hblsgindia.org/public_html/wp-content/plugins/redux-framework/redux-core/inc/classes/class-redux-functions-ex.php on line 312