XAMPP PHP 从本地主机发送电子邮件

我正在尝试从本地主机向本地主机（雷鸟帐户）发送消息，我正在按照本教程使用 XAMPP 如何使用汞....

我的 php.ini conf 是

    [mail function]
; For Win32 only.
; http://php.net/smtp
SMTP = localhost
; http://php.net/smtp-port
smtp_port = 25
; For Win32 only.
; http://php.net/sendmail-from
sendmail_from = postmaster@localhost
; For Unix only.  You may supply arguments as well (default: "sendmail -t -i").
; http://php.net/sendmail-path
;sendmail_path 

=

尽管如此，我仍然收到下一个错误

 Warning: mail(): SMTP server response: 421 Service not available, closing channel.