Fetches a user object by email address.
string $mail: String with the account's e-mail address.
object|bool A fully-loaded $user object upon successful user load or FALSE if user cannot be loaded.
function user_load_by_mail($mail) {
$users = entity_load_multiple_by_properties('user', array(
'mail' => $mail,
));
return $users ? reset($users)
->getBCEntity() : FALSE;
}