/*change email from wordpress at domain dot com */
add_filter('wp_mail_from', 'new_mail_from');
add_filter('wp_mail_from_name', 'new_mail_from_name');

function new_mail_from($old) {
 return 'noreply@yourdomain.com';
}
function new_mail_from_name($old) {
 return 'Whatever Name you want';
}