我有两个域名 Google Apps（为了论证的目的 - a.com 和 b.com）。
我已经根据 Google 针对这两个域名的推荐设置了 mx 记录。
我收到 a.com 上的所有电子邮件，而 b.com 上的大部分电子邮件都是我收到的。我之所以提到大部分，是因为有几位用户抱怨他们收到了来自 mailer-daemon 的消息
这是他们转发到我的 a.com 域的电子邮件（在我看来他们使用的是 Exchange），告知我他们发送到我的其他域的电子邮件无法发送。这告诉我它可能不是 Google 应用。
我看到他们的 SMTP 服务器正在尝试将此消息发送到 itservicecompany.com - 我不确定他们是谁 - 他们不是发件人。
From: MAILER-DAEMON
Sent: Wednesday, December 04, 2013 7:51 PM
To: [email protected]
Subject: Undeliverable: xxxx
Delivery has failed to these recipients or groups:
[email protected]
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address may only accept e-mail from certain senders, or another restriction may be preventing delivery.
The following organization rejected your message: mx1.emailsrvr.com.
Diagnostic information for administrators:
Generating server: smtp23.relay.ord1a.emailsrvr.com
[email protected]
mx1.emailsrvr.com #<mx1.emailsrvr.com #5.7.1 smtp; 550 5.7.1 <[email protected]>: Relay access denied.> #SMTP#
Original message headers:
Return-Path: <xxx.com>
Received: from smtp23.relay.ord1a.emailsrvr.com (localhost.localdomain [127.0.0.1])
by smtp23.relay.ord1a.emailsrvr.com (SMTP Server) with ESMTP id 7228E1C8265
for <**[email protected]>**; Wed, 4 Dec 2013 22:51:49 -0500 (EST)
X-SMTPDoctor-Processed: csmtpprox 2.7.4
Received: from localhost (localhost.localdomain [127.0.0.1])
by smtp23.relay.ord1a.emailsrvr.com (SMTP Server) with ESMTP id 6BF681C828B
for <**[email protected]**>; Wed, 4 Dec 2013 22:51:49 -0500 (EST)
X-Virus-Scanned: OK
Received: from smtp192.mex05.mlsrvr.com (unknown [184.106.31.85])
by smtp23.relay.ord1a.emailsrvr.com (SMTP Server) with ESMTPS id 54E1C1C8265
for <**[email protected]**>; Wed, 4 Dec 2013 22:51:49 -0500 (EST)
Received: from ORD2MBX02D.mex05.mlsrvr.com ([fe80::92e2:baff:fe0f:a9d0]) by
ORD2HUB08.mex05.mlsrvr.com ([fe80::d6ae:52ff:fe7f:6605%15]) with mapi id
14.03.0158.001; Wed, 4 Dec 2013 21:51:49 -0600
答案1
从您显示的标题来看：
Received: from smtp23.relay.ord1a.emailsrvr.com (localhost.localdomain [127.0.0.1])
by smtp23.relay.ord1a.emailsrvr.com (SMTP Server) with ESMTP id 7228E1C8265
for <**[email protected]>**; Wed, 4 Dec 2013 22:51:49 -0500 (EST)
因此，服务器使用的是 localhost.localdomain (127.0.0.1)，而不是服务器主机名的实际 IP 地址。这就是电子邮件被拒绝的原因。
要了解这一点，请检查SMTP 错误代码