我的 Postfix 设置了虚拟域。这样人们就可以向 *@mydomain.com 发送电子邮件，然后该邮件将被转发到我的 gmail 帐户。基本上，最终目标只是允许人们发送电子邮件[电子邮件保护]并且它会被转发给我，这样我就不用拥有单独的邮箱了。
在我安装的几天里，它一直运行良好，直到今天早上我醒来时发现我的 postfix 发来了几千封中国垃圾邮件。他们使用别名，例如[电子邮件保护]，[电子邮件保护]，[电子邮件保护]将邮件发送到完全不相关的外部电子邮件地址。澄清一下，这是第三方利用我的服务器滥用垃圾邮件。
我立刻惊慌失措，开始查找问题所在。/etc/passwd 中没有新用户，而 /etc/shadow 中只有我的用户、FTP 和 root 用户（禁用了 SSH）可以登录。因此，这似乎是 Postix 配置错误。
我似乎已经通过添加修复了
smtpd_client_restrictions = permit_mynetworks, reject
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated
# Block clients that speak too early.
smtpd_data_restrictions = reject_unauth_pipelining
# Enforce mail volume quota via policy service callouts.
smtpd_end_of_data_restrictions = check_policy_service unix:private/policy
到我的 main.cf。mail.log 仍然充满了所有这些尝试，但邮件不再被发送出去。示例
Aug 9 09:35:12 myusername postfix/smtpd[32085]: NOQUEUE: reject: RCPT from unknown[183.147.82.118]: 554 5.7.1 <unknown[183.147.82.118]>: Client host rejected: Access denied; from=<eff@mydomain$
Aug 9 09:35:14 myusername postfix/smtpd[32085]: lost connection after DATA from unknown[183.147.82.118]
Aug 9 09:35:14 myusername postfix/smtpd[32085]: disconnect from unknown[183.147.82.118]
现在的问题是，当我尝试向我的任何域发送任何内容时，它会阻止合法的电子邮件。
554 5.7.1 <mail-ob0-f172.google.com[209.85.214.172]>: Client host rejected: Access denied
我可以做什么
A）允许任何电子邮件发送到我的虚拟域（例如[电子邮件保护]) 转发到我的 Gmail 帐户，但不允许垃圾邮件发送者以某种方式使用我的服务器发送垃圾邮件。
并且可选 B) 首先停止所有这些可能的尝试，并弄乱我的 mail.log
这是我的 main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version
# Debian specific: Specifying a file name will cause the first
# line of that file to be used as the name. The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mydomain1.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
virtual_alias_domains = mydomain1.com, mydomain2.me
virtual_alias_maps = hash:/etc/postfix/virtual
myorigin = /etc/mailname
#mydestination = localhost.241.214.119, localhost
mydestination = $myhostname,localhost.$mydomain, localhost, $mydomain
#relayhost = mail.mydomain1.com
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_command = procmail -a "$EXTENSION"
mailbox_size_limit = 0
recipient_delimiter = +
inet_protocols = ipv4
milter_protocol = 2
milter_default_action = accept
smtpd_milters = inet:localhost:12301
non_smtpd_milters = inet:localhost:12301
smtp_generic_maps = hash:/etc/postfix/generic
smtpd_client_restrictions = permit_mynetworks, reject
# Spam control: exclude local clients and authenticated clients
# from DNSBL lookups.
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated
# Block clients that speak too early.
smtpd_data_restrictions = reject_unauth_pipelining
# Enforce mail volume quota via policy service callouts.
smtpd_end_of_data_restrictions = check_policy_service unix:private/policy
和我的master.cf
#
# Postfix master process configuration file. For details on the format
# of the file, see the master(5) manual page (command: "man 5 master" or
# on-line: http://www.postfix.org/master.5.html).
#
# Do not forget to execute "postfix reload" after editing this file.
#
# ==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (yes) (never) (100)
# ==========================================================================
smtp inet n - - - - smtpd
#smtp inet n - - - 1 postscreen
#smtpd pass - - - - - smtpd
#dnsblog unix - - - - 0 dnsblog
#tlsproxy unix - - - - 0 tlsproxy
#submission inet n - - - - smtpd
# -o syslog_name=postfix/submission
# -o smtpd_tls_security_level=encrypt
# -o smtpd_sasl_auth_enable=yes
# -o smtpd_reject_unlisted_recipient=no
# -o smtpd_client_restrictions=$mua_client_restrictions
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
# -o milter_macro_daemon_name=ORIGINATING
#smtps inet n - - - - smtpd
# -o syslog_name=postfix/smtps
# -o smtpd_tls_wrappermode=yes
# -o smtpd_sasl_auth_enable=yes
# -o smtpd_reject_unlisted_recipient=no
# -o smtpd_client_restrictions=$mua_client_restrictions
# -o smtpd_helo_restrictions=$mua_helo_restrictions
# -o smtpd_sender_restrictions=$mua_sender_restrictions
# -o smtpd_recipient_restrictions=
# -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
# -o milter_macro_daemon_name=ORIGINATING
#628 inet n - - - - qmqpd
pickup unix n - - 60 1 pickup
cleanup unix n - - - 0 cleanup
qmgr unix n - n 300 1 qmgr
#qmgr unix n - n 300 1 oqmgr
tlsmgr unix - - - 1000? 1 tlsmgr
rewrite unix - - - - - trivial-rewrite
bounce unix - - - - 0 bounce
defer unix - - - - 0 bounce
trace unix - - - - 0 bounce
verify unix - - - - 1 verify
flush unix n - - 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - - - - smtp
relay unix - - - - - smtp
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq unix n - - - - showq
error unix - - - - - error
retry unix - - - - - error
discard unix - - - - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - - - - lmtp
anvil unix - - - - 1 anvil
scache unix - - - - 1 scache
#
# ====================================================================
# Interfaces to non-Postfix software. Be sure to examine the manual
# pages of the non-Postfix software to find out what options it wants.
#
# Many of the following services use the Postfix pipe(8) delivery
# agent. See the pipe(8) man page for information about ${recipient}
# and other message envelope options.
# ====================================================================
#
# maildrop. See the Postfix MAILDROP_README file for details.
# Also specify in main.cf: maildrop_destination_recipient_limit=1
#
maildrop unix - n n - - pipe
flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# Recent Cyrus versions can use the existing "lmtp" master.cf entry.
#
# Specify in cyrus.conf:
# lmtp cmd="lmtpd -a" listen="localhost:lmtp" proto=tcp4
#
# Specify in main.cf one or more of the following:
# mailbox_transport = lmtp:inet:localhost
# virtual_transport = lmtp:inet:localhost
#
# ====================================================================
#
# Cyrus 2.1.5 (Amos Gouaux)
# Also specify in main.cf: cyrus_destination_recipient_limit=1
#
#cyrus unix - n n - - pipe
# user=cyrus argv=/cyrus/bin/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
# Old example of delivery via Cyrus.
#
#old-cyrus unix - n n - - pipe
# flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
uucp unix - n n - - pipe
flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
#
# Other external delivery methods.
#
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=Fq. user=bsmtp argv=/usr/lib/bsmtp/bsmtp -t$nexthop -f$sender $recipient
scalemail-backend unix - n n - 2 pipe
flags=R user=scalemail argv=/usr/lib/scalemail/bin/scalemail-store ${nexthop} ${user} ${extension}
mailman unix - n n - - pipe
flags=FR user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py
${nexthop} ${user}
任何见解都值得赞赏！
答案1
听起来你基本上是在运行一个开放中继，过了一会儿，一些垃圾邮件机器人发现了它并开始通过它发送电子邮件。
有几个 Postfix 设置可以关闭您的服务器。一个是允许网络选项。我通常只允许本地“已知”网络，然后将任何其他网络范围添加到我需要的本地列表中。
另一个是要求对邮件中继进行身份验证。
看起来您现在可能已经完成上述两件事并阻止了垃圾邮件转发。
对于任何面向互联网的邮件服务器，我所做的另一件事（这取决于您可以使用哪些安全设备）是运行动态更新的防火墙规则，该规则从公开已知的阻止列表（例如 spamhaus top 100）中获取地址并将其添加到防火墙的阻止规则中。
我为此使用了 pfSense 和 pfBlockerNG，非常有效。
汤姆