说明：  实现邮箱中对黑白名单的检测,同时进行数据库访问.先从邮件服务器中取出邮件的用户名称,然后一一与数据库中存储的黑白名单列表进行比较.先进行黑名单过滤,再进行白名单过滤,如果是黑名单则标记为"危险",白名单则标记为"安全".
(Realize-mail list of black and white detection, at the same time database access. From mail server to retrieve e-mail user name, and then one by one and stored in the database list of black and white list. Blacklist filter first and then whitelist filtering , if it is a blacklist is marked as )