如何停止SMTP server

Chinewei

今日用Nessus检索了一下自己的系统,发现了这样的信息:
Warning found on port ftp (21/tcp)
    This SMTP server is running on a non standard port.
    This might be a backdoor set up by crackers to send spam
    or even control your machine.
   
    Solution: Check and clean your configuration
    Risk factor : Medium
经过Google后,采取了下面的措施:
1)停止exim4运行
2)update-inetd --disable smtp
但还是nessus还是提示这些信息.
我该怎做才能停止smtp的运行呢?

iamif

运行rcconf，去掉exim4就可以了。