具体参考：
http://blog.xuite.net/sendohshih/blog/41958216-3%E5%88%86%E9%90%98%E8%BC%95%E9%AC%86%E6%93%81%E6%9C%89%E8%87%AA%E5%B7%B1%E7%9A%84Mail+Server
具体参考：
http://blog.xuite.net/sendohshih/blog/41958216-3%E5%88%86%E9%90%98%E8%BC%95%E9%AC%86%E6%93%81%E6%9C%89%E8%87%AA%E5%B7%B1%E7%9A%84Mail+Server