Hello friends,

Log in to WordPress using an Email Address – without using any addon.

Not required to install any third party addon.
Just you need to edit ONLY 2 LINES OF CODE.

Open wp-includes >> user.php
Look for below 2 lines, usually line no.29

if ( ! empty($_POST['log']) )
$credentials['user_login'] = $_POST['log'];


Just change that 2 lines with below.

if ( ! empty($_POST['log']) )
{
$user = get_user_by( 'email', $_POST['log'] );
if ( isset( $user, $user->user_login, $user->user_status ) && 0 == (int) $user->user_status ){ $_POST['log'] = $user->user_login; }
$credentials['user_login'] = $_POST['log'];
}


THATS IT.