我有一台服务器，不知何故，突然有大量电子邮件被拒绝，返回 550 5.7.1 NDR 或各种衍生代码。这种情况是几天前突然发生的。大量域名都出现了这种情况。起初我以为只是 GoDaddy 托管的电子邮件出现了问题，因为其中有几个是托管在那里的。然而，现在显然这个问题更加普遍。
我有：
- 检查 DNSBL 列表。
- 扫描本地电脑中的恶意软件/间谍软件。
- 已验证只有服务器可以通过防火墙发送 SMTP 流量。
- 通过管理员帐户发送电子邮件地址。
- 发送仅基于文本的电子邮件。
- 发送基于 HTML 的电子邮件。
- 发送基本电子邮件（没有附件，只有测试文本正文，没有签名）。
- 直接通过 OWA 发送电子邮件。
- 让收件人将域添加到 Outlook 中的安全发件人列表中。
- 已验证的 SPF 记录。
- 已验证的 rDNS 记录。
- 为了好玩，它改变了电子邮件流出的外部 IP 地址，但没有任何变化。
我没什么想法可以尝试。任何建议都将不胜感激。
此服务器直接连接到防火墙，防火墙不执行任何过滤。
我粘贴了一个 NDR 示例。真正奇怪的是，它看起来好像通过了所有垃圾邮件检查，并获得了 -4 的 SPF 评级，并提到它是安全发件人，然后就放弃了。
#< #5.7.1 smtp;550 5.7.1 Message rejected due to content restrictions> #SMTP#
Original message headers:
Received: from mail23-am1-R.bigfish.com ([161.7.8.25]) by DOAISD75213.mtdmz.ad
over TLS secured channel with Microsoft SMTPSVC(7.0.6002.18222); Fri, 21 Feb
2014 08:31:22 -0700
Received: from mail23-am1 (localhost [127.0.0.1])
by mail23-am1-R.bigfish.com (Postfix) with ESMTP id ADCFD1003A1
for <_________>; Fri, 21 Feb 2014 15:31:20 +0000 (UTC)
X-Forefront-Antispam-Report: CIP:69.146.164.109;KIP:(null);UIP:(null);IPV:NLI;H:mail.bearpaw.org;RD:mail.bearpaw.org;EFVD:NLI
X-SpamScore: -4
X-BigFish: vps-4(zz1861Ic89bh103dKa40Ic857hde40hzz1f42h2148h208ch1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah21bch1fc6hzz1de098h8275bh1de097h186068hz2fh109h2a8h839h8e2h8e3hd25h1288h12a5h12bdh137ah13eah1441h1504h1537h153bh15d0h162dh1631h1758h18e1h1946h19b5h1b0ah1bceh224fh1d0ch1d2eh1d3fh1dc1h1dfeh1dffh1e1dh1fe8h1ff5h20f0h2216h22d0h2336h2438h2461h2487h24d7h2516h2545h255ehbe9i34h1155h)
X-MS-Exchange-Organization-Force-TLS: 0
X-FFO-Routing-Override: mt.gov%161.7.8.28;
Received-SPF: pass (mail23-am1: domain of bearpaw.org designates 69.146.164.109 as permitted sender) client-ip=69.146.164.109; envelope-from=__________; helo=mail.bearpaw.org ;.bearpaw.org ;
X-MS-Exchange-Organization-Antispam-Report: OrigIP: 69.146.164.109;Service: EHS
Received: from mail23-am1 (localhost.localdomain [127.0.0.1]) by mail23-am1 (MessageSwitch) id 1392996678568717_17980; Fri, 21 Feb 2014 15:31:18 +0000 (UTC)
Received: from AM1EHSMHS006.bigfish.com (unknown [10.3.201.228])
by mail23-am1.bigfish.com (Postfix) with ESMTP id 7ADCB240079
for <_________>; Fri, 21 Feb 2014 15:31:18 +0000 (UTC)
Received: from mail.bearpaw.org (69.146.164.109) by AM1EHSMHS006.bigfish.com
(10.3.207.106) with Microsoft SMTP Server (TLS) id 14.16.227.3; Fri, 21 Feb
2014 15:31:15 +0000
Received: from SERVER.bpd.local ([fe80::50fe:d0bf:d57d:2f5d]) by
SERVER.bpd.local ([fe80::50fe:d0bf:d57d:2f5d%10]) with mapi; Fri, 21 Feb 2014
08:31:13 -0700
Content-Type: multipart/mixed;
boundary="_000_0D7E2AB4DAB13448A100F4A967F15C29010F798434DASERVERbpdlo_"
From:___________
To: _____________
Date: Fri, 21 Feb 2014 08:31:10 -0700
Subject: __________________________
Thread-Topic: _____________________________
Thread-Index: Ac8toIauLfTa3ulLRaCz4ClaFcUdMgArks5QAAS1bmAALg/IMA==
Message-ID: <[email protected]>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator: <[email protected]>
acceptlanguage: en-US
MIME-Version: 1.0
X-MS-Exchange-Organization-OriginalArrivalTime: 21 Feb 2014 15:31:15.9707
(UTC)
X-MS-Exchange-Organization-OriginalClientIPAddress: 69.146.164.109
X-MS-Exchange-Organization-OriginalServerIPAddress: 10.3.207.106
X-MS-Exchange-Organization-AuthSource: AM1EHSMHS006.ehs.local
X-MS-Exchange-Organization-AuthAs: Anonymous
X-MS-Exchange-Organization-MessageDirectionality: Incoming
X-MS-Exchange-Organization-ConnectorInfo: Dn%*$RO%0$FUIP%$LKIP%$KIPT%0$Id%0$Di%0$Tls%0$SF%0$PF%0$CF%0$FQDN%$TlsDn%$IpfH%IPV:NLI$EnfH%H:mail.bearpaw.org;RD:mail.bearpaw.org;EFVD:NLI$
X-MS-Exchange-Organization-Company-Id:
X-MS-Exchange-Organization-Attributed-Sender-Id:
X-MS-Exchange-Organization-OriginalSize: 283945
X-MS-Exchange-Organization-MessageScope: 00000000-0000-0000-0000-000000000000
X-MS-Exchange-Organization-HygienePolicy: Standard
X-MS-Exchange-Organization-MessageLatencyInProgress: LSRV=AM1EHSMHS006.ehs.local:TOTAL=2|SMR=2;2014-02-21T15:31:18.435Z
Return-Path: _____________________
X-OriginalArrivalTime: 21 Feb 2014 15:31:22.0430 (UTC) FILETIME=[F98A1DE0:01CF2F19]
非常感谢任何人提供的帮助！我非常感激！
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