限制特定用户收发邮件的高级访问控制方法

12/3/2006来源:Qmail人气:6819

一般邮件应用稍微有一电规模的企业,大多都会涉及到这样的应用需求:

某销售A只能收到来自163.com及sina.com的邮件某技术员B只能给内部用户发邮件,不允许向外网发邮件,但可以收到外网邮件某主管可以收发内、外网邮件......

如何实现呢?Postfix 1.x就已经可以通过配置实现这些功能了。

以下是邮件列表里Noel Jones 提出的解决方案:

Hello!

I have the same PRoblem:

1. I need to permit some internal users (not all) to send mail to any
external user (Internet)
2. I need to permite any external user to send mail to some my internal
users (not all)

In fact, the problem is: just "some" of my internal users have permission to
receive mail from and send mail to the Internet.

How can I solve this?

寄件者:Noel Jones ([email protected])
主旨:Re: RES: User Restriction.....


View this article only
新闻群组:mailing.postfix.users
日期:2002-12-04 15:18:04 PST

At 05:39 PM 12/4/02 -0200, [email protected] wrote:
>1. I need to permit some internal users (not all) to send mail to any
>external user (Internet)
>2. I need to permite any external user to send mail to some my internal
>users (not all)
>
>In fact, the problem is: just "some" of my internal users have permission
>to receive mail from and send mail to the Internet.
>
>How can I solve this?
>
>Thanks,
>Raissa

Restricting also who can receive mail from the internet changes the example
I posted a few minutes ago.

In the example below, the same list of restricted_users is used for
controlling both who can send and who can receive internet mail. If you
don't require the local_plus feature, just leave that part out.

  1. in main.cf:
  1. use restriction classes to make restricted_users file more readable.
    smtpd_restriction_classes = local_only, local_plus

local_only =
reject_unauth_destination
permit_mynetworks
reject

local_plus =
check_recipient_access hash:/etc/postfix/local_plus
check_sender_access hash:/etc/postfix/local_plus
reject_unauth_destination
permit_mynetworks
reject

  1. this is the default setting, required for this setup.
    smtpd_delay_reject = yes
  1. we'll do this in sender restrictions to avoid open relay problems.
    smtpd_sender_restrictions =
    check_sender_access hash:/etc/postfix/restricted_users
    check_recipient_access hash:/etc/postfix/restricted_users

and in /etc/postfix/restricted_users
# /etc/postfix/restricted_users
# this file contains a list of users only allowed to send and receive local
mail
# postmap this file after changes
# local users not listed here have no restrictions
[email protected] local_only
[email protected] local_plus

and in /etc/postfix/local_plus:
# /etc/postfix/local_plus
# this file contains allowed destinations and senders
# for users restricted to local_plus
# postmap this file after changes
miproveedor.com OK

Remember to "postmap local_plus" and "postmap restricted_users" after
making changes to them.
Remember to run "postfix reload" after changing main.cf

我自己常用的限制方法

有几个方法:

1) smtpd_restriction_classes = local_only
设置一个限制类别叫local_only,然后参考access(5)的格式做一个访问控制:

local_only = check_recipient_access hash:/etc/postfix/maps/my_rcpt

文件my_rcpt内容:

163.com RELAY21cn.com RELAYhzqbbc.com RELAY

然后,设置:

smtpd_sender_restrictions = check_sender_access hash:/etc/postfix/maps/mysender 

mysender内容:

[email protected]   local_only 

这样凡是Mail from:的信只能RCPT TO: 到163.com, 21cn.com及 hzqbbc.com 三个地方了。其他的都发不出去。

按这个方法,还可以设置更多的类别,例如remote_only以及不限制的帐号等。但这些都只对from:限制。而且不管是否SASL后的。所以有一定缺陷。不过,已经达到目的了。

2)使用snapshot版的policy策略
根据某个hash表或配置文件,判断对应的sender和recipient是否匹配,匹配就返回OK或者DUNNO或者RELAY等(可能RELAY已经过时,这个是postfix 1.1.x的)如果不匹配就返回错误代码

按postfix所带的smtpd-policy.pl模式,修改一下就可以使用了。详细参考POLICY_README等。

3)使用APF for postfix
详细地址:http://apf.org.cn/addon/

其实和2)方法是基本一致的。同样利用postfix内置的policy功能。