请教Postfix配置问题

[m4ker]

1. 邮件头中有以下内容（主要是指localhost，web3.novalocal，127.0.0.1等内容）是什么原因，如何设置才能显示正常的域名或者ip。

Received: by li414-36.localdomain (Postfix, from userid 48)
id B351D8BB9; Wed, 3 Apr 2013 08:43:12 +0000 (UTC)

Received: from web3.novalocal (localhost [127.0.0.1])
by www.360xxx.com (Postfix) with ESMTP id C2260160041
for <[e-mail]>; Sun, 7 Apr 2013 17:14:31 +0800 (CST)
Received: (from root@localhost)
by web3.novalocal (8.14.4/8.14.4/Submit) id r379ETHR023610;
Sun, 7 Apr 2013 17:14:29 +0800

2. 邮件服务器在内网并且没有端口映射，只发不收的话，会不会有什么问题？