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 [email protected]
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
Отличная статья. А на стороне Exchange какие должны быть произведены настройки? Где можно почитать об этом?
На стороне Exchange особо нечего настраивать, только коннекторы на прием и отправку. Такой статьи, к сожалению, у меня пока нет.