Postfix как пограничный relay для Exchange

Что бы не завалить Exchange кучей писем, я обычно устанавливаю пограничный сервер на Linux с Postfix и SpamAssassin. Такое решение позволяет еще на входе отфильтровать совсем уж спамвские письма и не нагружать ими внутренний сервер. При этом таких серверов лучше сразу поднять несколько для отказоустойчивости.
В качестве ОС я использую Centos 7. Проведя первоначальные настройки сервера приступим к установке Postfix и SpamAssassin.
yum -y install spamassassin postfix
systemctl enable spamassassin
systemctl enable postfix
Создаем каталоги и файлы для postfix
mkdir  /etc/postfix/db #каталог для баз
mkdir  /etc/postfix/ad #каталог для скриптов AD
mkdir  /etc/postfix/ssl #каталог  для сертификатов

В каталоге db у меня созданы такие файлы:
bad_clients — ручная блокировки мэйлов
good_clients — белый список
header_checks — для анализа заголовков
helo_regexp — для анализа helo
relay_domains — список доменов для пересылки
relay_recipients — список ящиков
virtual_transport — список smtp серверов (в нашем случае exchange)
Конвертируем эти файлы в индексированные базы для Postfix.
postmap bad_clients good_clients header_checks helo_regexp relay_domains relay_recipients virtual_transport
В каталог /etc/postfix/ssl нужно положить сертификат в формате .pem, хотя можно и в других. У меня этот сертификат от Lets Encrypt, но пойдут и самоподписные.
Далее я просто приведу пример Postfix конфигов:
main.cf
</pre>
smtpd_banner = $myhostname Microsoft ESMTP MAIL Service ready
biff = no

header_checks = regexp:/etc/postfix/db/header_checks

append_dot_mydomain = no

queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix

mail_owner = postfix

delay_warning_time = 1h
bounce_queue_lifetime = 1d
maximal_queue_lifetime = 2d

notify_classes = bounce, delay, policy, protocol, resource, software
bounce_notice_recipient = postf
error_notice_recipient = postf

readme_directory = no

smtpd_use_tls = yes
smtpd_tls_auth_only = yes
smtpd_tls_key_file=/etc/postfix/ssl/domain.key
smtpd_tls_cert_file=/etc/postfix/ssl/domain.pem
smtpd_tls_CAfile = /etc/postfix/ssl/domain.pem
smtpd_tls_loglevel = 3
smtpd_tls_received_header = yes
smtpd_tls_session_cache_timeout = 3600s
tls_random_source = dev:/dev/urandom
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache

smtp_use_tls = yes
smtp_tls_key_file=/etc/postfix/ssl/domain.key
smtp_tls_cert_file=/etc/postfix/ssl/domain.pem
smtp_tls_CAfile = /etc/postfix/ssl/domain.pem
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

smtpd_soft_error_limit = 5
smtpd_hard_error_limit = 10
smtpd_error_sleep_time = 1s

smtpd_client_restrictions =
check_client_access hash:/etc/postfix/db/good_clients,
check_client_access hash:/etc/postfix/db/bad_clients,
reject_rbl_client bl.spamcop.net,
reject_rbl_client zen.spamhaus.org,
permit

smtpd_helo_required = yes
smtp_always_send_ehlo = yes
smtpd_reject_unlisted_sender = yes

smtpd_helo_restrictions =
permit_mynetworks,
check_client_access hash:/etc/postfix/db/good_clients,
check_helo_access regexp:/etc/postfix/db/helo_regexp,
reject_invalid_helo_hostname,
reject_invalid_hostname,
reject_non_fqdn_helo_hostname,
permit

smtpd_sender_restrictions =
permit_mynetworks,
check_client_access hash:/etc/postfix/db/good_clients,
reject_non_fqdn_sender,
reject_rhsbl_sender dsn.rfc-ignorant.org,
permit

smtpd_recipient_restrictions =
permit_mynetworks,
check_client_access hash:/etc/postfix/db/good_clients,
reject_unauth_destination,
reject_non_fqdn_recipient,
reject_unauth_pipelining,
reject_unverified_sender,
permit

unknown_local_recipient_reject_code = 550
unknown_client_reject_code = 550
unknown_hostname_reject_code = 550
unknown_address_reject_code = 550

myhostname = mail.domain.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydomain = domain.com
myorigin = $mydomain
mydestination = localhost, mail.domain.com, $mydomain
relayhost =
mynetworks = 127.0.0.0/8 10.1.1.1 #ip Exchange
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all

message_size_limit = 40000000

local_recipient_maps =
virtual_transport = hash:/etc/postfix/db/virtual_transport
transport_maps = hash:/etc/postfix/db/virtual_transport
relay_domains = domain.com
relay_recipient_maps = hash:/etc/postfix/db/relay_recipients
<pre>
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").
#
# 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       -       n       -       -       smtpd -o content_filter=spamassassin
#smtp      inet  n       -       n       -       1       postscreen
#smtpd     pass  -       -       n       -       -       smtpd
#dnsblog   unix  -       -       n       -       0       dnsblog
#tlsproxy  unix  -       -       n       -       0       tlsproxy
#submission inet n       -       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=$mua_sender_restrictions
#  -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#smtps     inet  n       -       n       -       -       smtpd
#  -o syslog_name=postfix/smtps
#  -o smtpd_tls_wrappermode=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_reject_unlisted_recipient=no
#  -o smtpd_client_restrictions=$mua_client_restrictions
#  -o smtpd_helo_restrictions=$mua_helo_restrictions
#  -o smtpd_sender_restrictions=$mua_sender_restrictions
#  -o smtpd_recipient_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#628       inet  n       -       n       -       -       qmqpd
pickup    unix  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      unix  n       -       n       300     1       qmgr
#qmgr     unix  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       n       1000?   1       tlsmgr
rewrite   unix  -       -       n       -       -       trivial-rewrite
bounce    unix  -       -       n       -       0       bounce
defer     unix  -       -       n       -       0       bounce
trace     unix  -       -       n       -       0       bounce
verify    unix  -       -       n       -       1       verify
flush     unix  n       -       n       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       n       -       -       smtp
relay     unix  -       -       n       -       -       smtp
#       -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq     unix  n       -       n       -       -       showq
error     unix  -       -       n       -       -       error
retry     unix  -       -       n       -       -       error
discard   unix  -       -       n       -       -       discard
local     unix  -       n       n       -       -       local
virtual   unix  -       n       n       -       -       virtual
lmtp      unix  -       -       n       -       -       lmtp
anvil     unix  -       -       n       -       1       anvil
scache    unix  -       -       n       -       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/local/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=/usr/lib/cyrus-imapd/deliver -e -r ${sender} -m ${extension} ${user}
#
# ====================================================================
#
# Old example of delivery via Cyrus.
#
#old-cyrus unix  -       n       n       -       -       pipe
#  flags=R user=cyrus argv=/usr/lib/cyrus-imapd/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/local/sbin/bsmtp -f $sender $nexthop $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}

spamassassin unix - n n - - pipe
    user=spamd argv=/usr/bin/spamc -f -e
        /usr/sbin/sendmail -oi -f ${sender} ${recipient}
header_checks
/^Subject:.*SPAM/ REDIRECT spam@domain.com
helo_regexp
/([0-9]{1,3}(\.|-)){3}[0-9]{1,3}/i REJECT Dynamic address
relay_domains
domain.com OK
virtual_transport
domain.com smtp:[10.1.1.1]
Теперь немного настроим SpamAssassin
adduser --system spamd
mkdir /home/spamd/.spamassassin/
vim /home/spamd/.spamassassin/user_prefs #просто создаем пустой файл
Настроим firewall для 25 порта:
firewall-cmd --zone=public --add-service=smtp --permanent
firewall-cmd --reload
Запустим сервисы:
systemctl start spamassassin
systemctl start postfix

Добавить комментарий

Ваш e-mail не будет опубликован. Обязательные поля помечены *