NMSMTP我開始用的CHARSET=un-ascii,出現的情況就是亂碼,後設為un-unicode，
出現的情況如下：
This message uses a character set that is not supported by the Internet
Service. To view the original message content, open the attached
message. If the text doesn't display correctly, save the attachment to
disk, and then open it using a viewer that can display the original
character set. <<message.txt>>
而message.txt的內容如下：
Received: from exzs.pyzs.com.cn (localhost [127.0.0.1]) by exzs.pyzs.com.cn with SMTP (Microsoft Exchange Internet Mail Service Version 5.5.2653.13)
id ZATX41TT; Sun, 22 Dec 2002 21:39:54 +0800
Received: from 172.18.7.127 by exzs.pyzs.com.cn (InterScan E-Mail VirusWall NT); Sun, 22 Dec 2002 21:39:54 +0800
From: li_lip<ads@qw>
To: li_lip@pyzs.com.cn
Subject: 你好晚上好 //此為我發送的主題
Mime-Version: 1.0
Content-Type: text/plain; charset=us-unicode
你好,你好晚上好 //此為我發送的正文
