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OsakaWebbie
Asked: 2016-09-12 21:15:10 +0800 CST

如何将后缀设置为仅忽略发给不存在用户的邮件

  • 772

我收到了大量针对随机用户名的垃圾邮件尝试。我知道这在某种程度上发生在所有邮件服务器上，但是在过去的两周里，我的 VPS 磁盘分配空间太大了，仅仅因为邮件日志文件的大小就被填满了！一周的日志差不多有7GB，其他的小一些但不正常。我是阅读日志的新手，但这里有一个随机选择的小片段：

Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 05DEA31470BF: from=<[email protected]>, size=1165, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 05DEA31470BF: to=<[email protected]>, relay=none, delay=358802, delays=358802/0.07/0/0, dsn=4.4.2, status=deferred (delivery temporarily suspended: lost connection with mta5.am0.yahoodns.net[66.196.118.34] while sending RCPT TO)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 00B053186BAE: from=<[email protected]>, size=1123, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27246]: 00DAD31454C1: to=<[email protected]>, relay=local, delay=391867, delays=391867/0.13/0/0.02, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "ginger_walton")
Sep 11 03:53:16 vps-1011517-5697 postfix/smtp[26812]: 0099B3136B26: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[74.125.204.27]:25, delay=107076, delays=107075/0/0.39/0.68, dsn=4.7.1, status=SOFTBOUNCE (host gmail-smtp-in.l.google.com[74.125.204.27] said: 550-5.7.1 [27.112.107.68       1] Our system has detected an unusual rate of 550-5.7.1 unsolicited mail originating from your IP address. To protect our 550-5.7.1 users from spam, mail sent from your IP address has been blocked. 550-5.7.1 Please visit 550-5.7.1  https://support.google.com/mail/?p=UnsolicitedIPError to review our 550 5.7.1 Bulk Email Senders Guidelines. q189si11097060pfq.189 - gsmtp (in reply to end of DATA command))
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 00ECD3169334: from=<[email protected]>, size=1106, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 00ECD3169334: to=<[email protected]>, relay=none, delay=246340, delays=246340/0.02/0/0, dsn=4.4.2, status=deferred (delivery temporarily suspended: lost connection with mta5.am0.yahoodns.net[66.196.118.34] while sending RCPT TO)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 0231E3138414: from=<[email protected]>, size=1560, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 0231E3138414: to=<[email protected]>, relay=none, delay=14482, delays=14482/0/0/0, dsn=4.4.2, status=deferred (delivery temporarily suspended: lost connection with mta5.am0.yahoodns.net[66.196.118.34] while sending RCPT TO)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 062593144D72: from=<>, size=3463, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 08A1D31498F3: from=<>, size=3045, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27247]: 062593144D72: to=<[email protected]>, relay=local, delay=396966, delays=396966/0.01/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "isabel_miles")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 0D692313F1DA: from=<>, size=3078, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 00EA0313F88E: from=<>, size=3464, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27248]: 08A1D31498F3: to=<[email protected]>, relay=local, delay=321787, delays=321787/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "bridget_harrison")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 0F2A33147B48: from=<>, size=3657, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27246]: 0D692313F1DA: to=<[email protected]>, relay=local, delay=430240, delays=430240/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "freda_gordon")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 046C83133878: from=<[email protected]>, size=1180, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27247]: 00EA0313F88E: to=<[email protected]>, relay=local, delay=425180, delays=425180/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "amelia_hanson")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 035633144D87: from=<>, size=3087, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 019673137E30: from=<[email protected]>, size=1161, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27248]: 0F2A33147B48: to=<[email protected]>, relay=local, delay=347073, delays=347073/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "della_wright")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 01F593146A8D: from=<>, size=3579, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27246]: 035633144D87: to=<[email protected]>, relay=local, delay=396952, delays=396952/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "kelley_strickland")
Sep 11 03:53:16 vps-1011517-5697 postfix/smtp[27074]: 0423D31361AE: to=<[email protected]>, relay=mx3.hotmail.com[65.55.37.72]:25, delay=33557, delays=33557/0.01/0.38/0.12, dsn=4.0.0, status=SOFTBOUNCE (host mx3.hotmail.com[65.55.37.72] said: 550 SC-002 (COL004-MC1F20) Unfortunately, messages from 27.112.107.68 weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors. (in reply to MAIL FROM command))
Sep 11 03:53:16 vps-1011517-5697 postfix/smtp[27074]: 0423D31361AE: lost connection with mx3.hotmail.com[65.55.37.72] while sending RCPT TO
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 078CF312D56D: from=<>, size=3751, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27247]: 01F593146A8D: to=<[email protected]>, relay=local, delay=371261, delays=371261/0.02/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "eva_morrison")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 0CB143130F4A: from=<>, size=3022, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27248]: 078CF312D56D: to=<[email protected]>, relay=local, delay=321700, delays=321700/0.01/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "gwen_mendoza")
Sep 11 03:53:16 vps-1011517-5697 postfix/qmgr[31514]: 02A0C31284D7: from=<>, size=3032, nrcpt=1 (queue active)
Sep 11 03:53:16 vps-1011517-5697 postfix/local[27246]: 0CB143130F4A: to=<[email protected]>, relay=local, delay=242903, delays=242903/0.01/0/0, dsn=4.1.1, status=SOFTBOUNCE (unknown user: "marcia_harvey")

三个沉思：

  • 我对“SOFTBOUNCE”的理解不适合这种情况——无效的用户名应该是硬退回，对吧？无论如何，我宁愿根本没有任何反弹，因为这既浪费资源又给垃圾邮件发送者太多信息。
  • 我不明白来自 Google 服务器的投诉文本 - 句子中似乎随机插入了数字“500-5.7.1”。但我认为如果有足够多的这些传出的反弹，它们本身就可以被解释为垃圾邮件，对吧？
  • 来自 French Hotmail 的关于阻止列表的投诉可能是由我的服务器或其他人的服务器引起的；对 107 个黑名单的检查仅在其中两个上报告了我的 IP，所以我认为我的网站上没有真正的垃圾邮件生成器或类似的东西。

无论如何，我在域上只有一个有效的用户名，所以是否可以配置 postfix 以简单地将任何邮件尝试丢弃到任何其他用户名？如果没有发送退回邮件，甚至没有在日志文件中输入任何内容，我会很高兴，因为正如我所说，日志文件本身正在填满。或者，如果有更好的方法来处理这种攻击，我会全神贯注。

编辑#1：针对询问连接/断开连接条目的评论，我搜索了第一次出现的“连接”（周围有空格 - 否则我会得到所有“丢失的连接”条目），然后grepped后续引用同一个邮件服务器。这是其中的第一个序列，发生在两秒内，因此可能与同一电子邮件尝试有关：

Sep 11 03:53:25 vps-1011517-5697 postfix/smtpd[20505]: connect from simcoe209srvr.owm.bell.net[184.150.200.209]
Sep 11 03:53:25 vps-1011517-5697 postfix/smtpd[20505]: setting up TLS connection from simcoe209srvr.owm.bell.net[184.150.200.209]
Sep 11 03:53:26 vps-1011517-5697 postfix/smtpd[20505]: TLS connection established from simcoe209srvr.owm.bell.net[184.150.200.209]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bi
ts)
Sep 11 03:53:26 vps-1011517-5697 postfix/smtpd[20505]: NOQUEUE: reject: RCPT from simcoe209srvr.owm.bell.net[184.150.200.209]: 450 4.1.1 <[email protected]>: Recipient address
 rejected: User unknown in local recipient table; from=<> to=<[email protected]> proto=ESMTP helo=<torfep04.bell.net>
Sep 11 03:53:27 vps-1011517-5697 postfix/smtpd[20505]: disconnect from simcoe209srvr.owm.bell.net[184.150.200.209]

这些不是日志中的连续条目；在相同的两秒钟内有大量不相关的条目。但是，如果您要我在其中搜索相关的内容，请告诉我要查找的内容。

编辑#2：作为对 JennyD 的回应，这是我的 /etc/postfix/main.cf （当然删除了评论）：

soft_bounce = yes
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
mail_owner = postfix
myhostname = l4jp.com
mydomain = l4jp.com
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain
unknown_local_recipient_reject_code = 550
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
debug_peer_level = 2
debugger_command =
         PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
         xxgdb $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.3.3/samples
readme_directory = /usr/share/doc/postfix-2.3.3/README_FILES
# THE FOLLOWING IS FROM: http://www.anchor.com.au/hosting/dedicated/Postfix-SASL-setup
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_sasl_authenticated_header = yes
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions =
    permit_mynetworks
    permit_sasl_authenticated
    reject_unauth_destination
smtpd_tls_security_level = may
smtpd_tls_key_file = /etc/ssl/smtpd.key
smtpd_tls_cert_file = /etc/ssl/smtpd.crt
smtpd_tls_auth_only = yes
smtpd_tls_loglevel = 1
smtpd_tls_received_header = yes
#My settings for virtual mailbox domains (which I don't think I actually use for anything)
virtual_mailbox_domains = /etc/postfix/vhosts.txt
virtual_mailbox_base = /var/spool/vmail
virtual_mailbox_maps = hash:/etc/postfix/vmaps.txt
virtual_minimum_uid = 100
virtual_uid_maps = static:101
virtual_gid_maps = static:101
message_size_limit = 30720000

编辑#3： Dom 推荐 softbounce=no。我在进行更改之前和之后发送了一封测试电子邮件 - 以下是相关的日志条目（发件人地址已清理）：

Sep 12 20:38:39 vps-1011517-5697 postfix/smtpd[5343]: connect from gateway21.websitewelcome.com[192.185.45.43]
Sep 12 20:38:39 vps-1011517-5697 postfix/smtpd[5343]: setting up TLS connection from gateway21.websitewelcome.com[192.185.45.43]
Sep 12 20:38:39 vps-1011517-5697 postfix/smtpd[5343]: TLS connection established from gateway21.websitewelcome.com[192.185.45.43]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Sep 12 20:38:40 vps-1011517-5697 postfix/smtpd[5343]: NOQUEUE: reject: RCPT from gateway21.websitewelcome.com[192.185.45.43]: 450 4.1.1 <[email protected]>: Recipient address rejected: User unknown in local recipient table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<gateway21.websitewelcome.com>
Sep 12 20:38:40 vps-1011517-5697 postfix/smtpd[5343]: disconnect from gateway21.websitewelcome.com[192.185.45.43]

Sep 12 20:43:06 vps-1011517-5697 postfix/smtpd[6400]: connect from gateway23.websitewelcome.com[192.185.50.119]
Sep 12 20:43:06 vps-1011517-5697 postfix/smtpd[6400]: setting up TLS connection from gateway23.websitewelcome.com[192.185.50.119]
Sep 12 20:43:07 vps-1011517-5697 postfix/smtpd[6400]: TLS connection established from gateway23.websitewelcome.com[192.185.50.119]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Sep 12 20:43:07 vps-1011517-5697 postfix/smtpd[6400]: NOQUEUE: reject: RCPT from gateway23.websitewelcome.com[192.185.50.119]: 550 5.1.1 <[email protected]>: Recipient address rejected: User unknown in local recipient table; from=<[email protected]> to=<[email protected]> proto=ESMTP helo=<gateway23.websitewelcome.com>
Sep 12 20:43:07 vps-1011517-5697 postfix/smtpd[6400]: disconnect from gateway23.websitewelcome.com[192.185.50.119]

在这两种情况下都有五个条目 - 日志中的唯一区别是错误代码（如预期的那样）。但是在更改之后，我收到了一条实际退回邮件到我发送测试的地址。发送给垃圾邮件发送者不是一件坏事吗？

编辑#4：响应 masegaloeh 的评论，要求提供与同一消息队列 ID 相关的所有条目。他作为示例给出的 ID 来自我关闭 soft_bounce 之前的原始文件，但我怀疑没有 soft_bounce 的 ID 更有用，所以这里是一个最近的随机示例：

[root](10:27:06)[~]$ grep E6CBF312663B /var/log/maillog
Sep 15 10:26:11 vps-1011517-5697 postfix/cleanup[10347]: E6CBF312663B: message-id=<[email protected]>
Sep 15 10:26:11 vps-1011517-5697 postfix/bounce[10292]: 47A8E3126F85: sender non-delivery notification: E6CBF312663B
Sep 15 10:26:11 vps-1011517-5697 postfix/qmgr[8701]: E6CBF312663B: from=<>, size=3801, nrcpt=1 (queue active)
Sep 15 10:26:11 vps-1011517-5697 postfix/local[10477]: E6CBF312663B: to=<[email protected]>, relay=local, delay=0, delays=0/0/0/0, dsn=5.1.1, status=bounced (unknown user: "eula_mcdonald")
Sep 15 10:26:11 vps-1011517-5697 postfix/qmgr[8701]: E6CBF312663B: removed

当前的日志文件仅用了大约 2.5 天就增长到了 1.2GB。我无法承受这样的速度……

编辑#5：接下来，masegaloeh 要求这样做：

[root](09:03:50)[/var/log]$ grep 47A8E3126F85 maillog
Sep 15 10:26:10 vps-1011517-5697 postfix/pickup[10444]: 47A8E3126F85: uid=500 from=<[email protected]>
Sep 15 10:26:10 vps-1011517-5697 postfix/cleanup[10347]: 47A8E3126F85: message-id=<[email protected]>
Sep 15 10:26:10 vps-1011517-5697 postfix/qmgr[8701]: 47A8E3126F85: from=<[email protected]>, size=1153, nrcpt=1 (queue active)
Sep 15 10:26:11 vps-1011517-5697 postfix/smtp[9981]: 47A8E3126F85: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[64.233.189.27]:25, delay=1.7, delays=0.02/0.39/0.51/0.75, dsn=5.7.1, status=bounced (host gmail-smtp-in.l.google.com[64.233.189.27] said: 550-5.7.1 [27.112.107.68       1] Our system has detected an unusual rate of 550-5.7.1 unsolicited mail originating from your IP address. To protect our 550-5.7.1 users from spam, mail sent from your IP address has been blocked. 550-5.7.1 Please visit 550-5.7.1  https://support.google.com/mail/?p=UnsolicitedIPError to review our 550 5.7.1 Bulk Email Senders Guidelines. n130si231260oig.169 - gsmtp (in reply to end of DATA command))
Sep 15 10:26:11 vps-1011517-5697 postfix/bounce[10292]: 47A8E3126F85: sender non-delivery notification: E6CBF312663B
Sep 15 10:26:11 vps-1011517-5697 postfix/qmgr[8701]: 47A8E3126F85: removed

编辑#6：在采取迈克尔汉普顿建议的行动之后，我再次查看了日志的尾部。“接受投递”这句话引起了我的注意，因为我没有发送或接收任何真正的邮件 - 这是与我注意到的那个相关的系列：

[root](15:01:16)[/var/log]$ grep 638BD3122039 maillog
Sep 17 14:59:34 vps-1011517-5697 postfix/pickup[8959]: 638BD3122039: uid=500 from=<[email protected]>
Sep 17 14:59:34 vps-1011517-5697 postfix/cleanup[9099]: 638BD3122039: message-id=<[email protected]>
Sep 17 14:59:34 vps-1011517-5697 postfix/qmgr[7492]: 638BD3122039: from=<[email protected]>, size=1185, nrcpt=1 (queue active)
Sep 17 14:59:38 vps-1011517-5697 postfix/smtp[9109]: 638BD3122039: to=<[email protected]>, relay=gw-eur1.smtp.philips.com[212.159.218.9]:25, delay=3.6, delays=0.07/0.01/1.6/2, dsn=2.0.0, status=sent (250 2.0.0 kVzb1t0041UaJoz01VzcmY mail accepted for delivery)
Sep 17 14:59:38 vps-1011517-5697 postfix/qmgr[7492]: 638BD3122039: removed

当然这里没有 juanita_ellis。什么可能导致该消息被发送？我真的发送垃圾邮件？？？

logging spam postfix email-bounces

1 个回答

  1. Best Answer

    我没有mynetworks =在您的 Postfix 配置中看到指定main.cf。

    如果未指定，则与您位于同一本地网络的任何人都可以通过您的服务器中继邮件而无需身份验证，从而使您的邮件服务器至少在某种程度上是开放的中继。如果您的系统有一个全球 IP 地址，例如因为您托管在某种 VPS 提供商（如 Digital Ocean）上，那么这使得它容易受到附近机器的攻击，这些机器托管在同一提供商处。

    这应该立即修复。

    将其锁定以便只有本地主机可以通过服务器发送未经身份验证的邮件：

    mynetworks = 127.0.0.0/8 [::1]/128

    另外，考虑删除服务器上所有排队的邮件（垃圾邮件！），这样 Postfix 就不会尝试重新发送它。

    查看队列，mailq如果您没有看到任何合法的内容，请使用 删除所有内容postsuper -d ALL。

    您的最后一次编辑清楚地表明您系统上的本地进程正在生成邮件。该进程以 uid 500 运行，这很可能是您的帐户。所以看起来你已经被妥协了。从轨道上用核弹发射它；这是唯一确定的方法。

    • 3

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