读取的反抄本条目user_register action, 上面写着：

触发此操作时，并非所有用户元数据都存储在数据库中。

请注意，执行以下操作：

$user = wp_insert_user( $userdata );
update_user_meta( $user, \'companyId\', 350 );

因此，在wp_insert_user(), 你可以在user_register 措施：

add_action( \'user_register\', \'sendMailM\' );
function sendMailM( $user_id ) {

    // Note: $_POST data is available here,
    // just in case you need to update user meta based on form input,
    // for example, $_POST[\'companyId\']
    update_user_meta( $user_id, \'companyId\', 350 );

    $title  = "Title";
    $from   = "noreply@admin.no";

    global $wpdb, 
        $password;

    $user       = new WP_User( $user_id );
    $user_login = stripslashes( $user->user_login );
    $user_email = stripslashes( $user->user_email );
    // You can now access to previously updated user meta
    // Or get the companyId directly from $_POST input if needed
    $companyCreatedUserP4 = get_user_meta( $user_id, \'companyId\', true );

    if( ! empty( $companyCreatedUserP4 ) )
    {
        $current_companyP4  = new WP_User( $companyCreatedUserP4 );
        $companyEmailP4     = $current_companyP4->user_email;
        $messageAdmin       = \'New User \' . $user_login . \' is registered on your site under \' . $current_companyP4->user_firstname . \' company.\';
        $messageCompanyP4   = \'A new user with a user name: \' . $user_login . \' was registered under your company.\';
    }
    else
    {
        $messageAdmin = \'New User \' . $user_login . \' is registered on your site.\'; 
    }

    $message  = "<p>You are now registered . Your user name and password are included in this email. </p>";
    $message .= "<p>" . sprintf( __( \'Username: %s\' ), $user_login ) . "\\r\\n\\r\\n</p>";
    $message .= "<p>" . sprintf( __( \'Password: %s\' ), $passwor d) . "\\r\\n</p>";

    $headers = \'From: \' . $title . \'<\' . $from . ">\\r\\nReply-To: " . $from;
    add_filter( \'wp_mail_content_type\', create_function( \'\', \'return "text/html";\' ) );
    wp_mail( get_option( \'admin_email\' ), \'New User Registration \', $messageAdmin, $headers );  /*admin*/

    if( ! empty( $companyEmailP4 ) )
        wp_mail( $companyEmailP4, \'New User Registration \', $messageCompanyP4, $headers );      /*user*/
}