在局域网内玩postfix的设置

[gaintele]

老板让用postfix作邮件服务器，用mailman搭建邮件列表，
又不给域名，让先在局域网内搭好，
可怜我菜鸟一个，google了一个多星期了，postfix还是没弄好，网上教程一大堆都是说有域名的
教程上一共就这几行配置：
* General type of mail configuration: Internet Site
* NONE doesn't appear to be requested in current config
* System mail name: server1.example.com
* Root and postmaster mail recipient: <admin_user_name>
* Other destinations for mail: server1.example.com, example.com, localhost.example.com, localhost
* Force synchronous updates on mail queue?: No
* Local networks: 127.0.0.0/8
* Yes doesn't appear to be requested in current config
* Mialbox size limit (bytes): 0
* Local address extension character: +
* Internet protocols to use: all
我能想到的配置是这些了：
* General type of mail configuration: Local only
* NONE doesn't appear to be requested in current config
* System mail name: ？
* Root and postmaster mail recipient: ？
* Other destinations for mail:？
* Force synchronous updates on mail queue?: No
* Local networks: 127.0.0.0/8
* Yes doesn't appear to be requested in current config
* Mialbox size limit (bytes): 0
* Local address extension character: +
* Internet protocols to use: all
确实不晓得怎么替换，大侠们帮帮忙阿
假设我机器的内网ip是192.20.0.2

[dwl301]

自己整个DNS吧。。。。。。。。

[gaintele]

楼上的大侠是说弄个虚拟域名么，linux我就没玩几天阿，大侠说明白点吧，或者指个路我自己google去，感激不尽阿

[gaintele]

有人在么？怎么这么冷清阿
我现在能在本机内给不同的用户域发邮件了
但是在局域网内还是不行阿

看网上说先自己胡编一个域名，等有了再填真域名，我就编了一个ictliu.com，
但是不管是本机还是其他主机telnet访问都不行：
root@yang_desktop:~# telnet mail.ictliu.com 25
telnet: could not resolve mail.ictliu.com/25: Name or service not known
我这里只有网内的IP 是不是还得到局域网的DNS服务器上注册一下我这个胡诌的域名阿

盼达人指点迷津阿