<?php
//Access from front side
if ( isset( $_POST['msg'] ) ) {

 //get wordpress core
 include_once( $_SERVER['DOCUMENT_ROOT'] . '/wp-config.php' );

 //send massage
 $message  = 'Hi,' . PHP_EOL . PHP_EOL . $_POST['msg'] . PHP_EOL . PHP_EOL . __( 'From', 'agpl' ) . PHP_EOL . $_POST['name'] . PHP_EOL . $_POST['email'] . PHP_EOL . PHP_EOL . PHP_EOL . __( 'Submitted From', 'agpl' ) . PHP_EOL . __( 'IP Address', 'agpl' ) . ' : ' . $_POST['ip'] . PHP_EOL . __( 'Device (Browser and OS)', 'agpl' ) . ' : ' . $_POST['user'] . PHP_EOL . PHP_EOL;
 $headers  = 'From: ' . $_POST['name'] . PHP_EOL;
 $headers .= 'Content-type: text/html; charset=UTF-8' . PHP_EOL;
 $headers .= 'Content-Transfer-Encoding: quoted-printable' . PHP_EOL;
 $headers .= 'Reply To: ' . $_POST['name'] . ' <' . $_POST['email'] . '>' . PHP_EOL;
 $auto_mail = wp_mail( get_bloginfo( 'admin_email'), 'New Message Submitted in ' . get_bloginfo('name'), $message, $headers );

//Access from admin side
} else {
 get_template_part( '404' );
}
?>