我在設定 postfix 使用正確的 SSL 憑證在連接埠 25 上偵聽幾個（實際上是 3 個）IP 位址時遇到問題。
背景：我使用 Debian 11，使用 Postfix（來自 repo 的 v 3.5.6）/Dovecot 和 ISPConfig 作為託管面板。我有幾個工作正常的 IP 位址，有記錄 A 指向 IP 的域名，以及每個 IP 的正確 revDNS。每個網域都產生了正確的憑證以供使用。防火牆配置正確，幾乎一切都按我的預期運作。
我目前的狀態是 Postfix 在所有定義的 IP 位址（包括 127.0.0.1）上正確偵聽連接埠 465 和 587 - 並且還在該連接埠上以正確的憑證進行回應。但在連接埠 25 上，它始終使用第一個網域的憑證 - 即使連接到其他 IP（網域）時也是如此。 Dovecot 也使用憑證（但配置 Dovecot 非常容易，而且它的運作方式與 IMAP 和 POP3 的工作方式類似）。我不知道我在哪裡配置 Postfix 時出錯了。我唯一不想做的一件事是 postfix“多個實例” - 因為 ISPConfig 根本不支援它們（它甚至根本不支援 Dovecot/Postfix 的多個 IP，或者它們的任何一種 SNI） 。
我目前的配置如下所示：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 $mail_name (Debian/GNU)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = /usr/share/doc/postfix
# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2
# TLS parameters
#
# smtpd_tls_cert_file = /etc/postfix/smtpd.cert
# smtpd_tls_key_file = /etc/postfix/smtpd.key
smtpd_tls_security_level = may
smtp_tls_CApath=/etc/ssl/certs
smtp_tls_security_level = dane
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
myhostname = domain1.com
alias_maps = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
alias_database = hash:/etc/aliases, hash:/var/lib/mailman/data/aliases
myorigin = /etc/mailname
mydestination = domain1.com, localhost, localhost.localdomain
relayhost =
mynetworks = 127.0.0.0/8 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
# OEYG inet_interfaces = all
inet_interfaces = 127.0.0.1 xx.xx.xx.x1 xx.xx.xx.x2 xx.xx.xx.x3
# ORYG inet_protocols = all
inet_protocols = ipv4
html_directory = /usr/share/doc/postfix/html
virtual_alias_domains = proxy:mysql:/etc/postfix/mysql-virtual_alias_domains.cf
virtual_alias_maps = hash:/var/lib/mailman/data/virtual-mailman, proxy:mysql:/etc/postfix/mysql-virtual_forwardings.cf, proxy:mysql:/etc/postfix/mysql-virtual_alias_maps.cf, proxy:mysql:/etc/postfix/mysql-virtual_email2email.cf
virtual_mailbox_domains = proxy:mysql:/etc/postfix/mysql-virtual_domains.cf
virtual_mailbox_maps = proxy:mysql:/etc/postfix/mysql-virtual_mailboxes.cf
virtual_mailbox_base = /var/vmail
virtual_uid_maps = proxy:mysql:/etc/postfix/mysql-virtual_uids.cf
virtual_gid_maps = proxy:mysql:/etc/postfix/mysql-virtual_gids.cf
sender_bcc_maps = proxy:mysql:/etc/postfix/mysql-virtual_outgoing_bcc.cf
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_authenticated_header = yes
smtpd_restriction_classes = greylisting
greylisting = check_policy_service inet:127.0.0.1:10023
smtpd_recipient_restrictions = permit_mynetworks, reject_unknown_recipient_domain, reject_unlisted_recipient, permit_sasl_authenticated, reject_non_fqdn_recipient, reject_unauth_destination, check_recipient_access proxy:mysql:/etc/postfix/mysql-virtual_recipient.cf, check_recipient_access mysql:/etc/postfix/mysql-virtual_policy_greylist.cf, check_policy_service unix:private/quota-status
smtpd_use_tls = yes
transport_maps = hash:/var/lib/mailman/data/transport-mailman, proxy:mysql:/etc/postfix/mysql-virtual_transports.cf
relay_domains = proxy:mysql:/etc/postfix/mysql-virtual_relaydomains.cf
relay_recipient_maps = proxy:mysql:/etc/postfix/mysql-virtual_relayrecipientmaps.cf
smtpd_sender_login_maps = proxy:mysql:/etc/postfix/mysql-virtual_sender_login_maps.cf
proxy_read_maps = $local_recipient_maps $mydestination $virtual_alias_maps $virtual_alias_domains $sender_bcc_maps $virtual_mailbox_maps $virtual_mailbox_domains $relay_recipient_maps $relay_domains $canonical_maps $sender_canonical_maps $recipient_canonical_maps $relocated_maps $transport_maps $mynetworks $smtpd_sender_login_maps $virtual_uid_maps $virtual_gid_maps $smtpd_client_restrictions $smtpd_sender_restrictions $smtpd_recipient_restrictions $smtp_sasl_password_maps $sender_dependent_relayhost_maps
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks, check_helo_access regexp:/etc/postfix/helo_access, permit_sasl_authenticated, reject_invalid_helo_hostname, reject_non_fqdn_helo_hostname, check_helo_access regexp:/etc/postfix/blacklist_helo, reject_unknown_helo_hostname, permit
smtpd_sender_restrictions = permit_mynetworks, check_sender_access proxy:mysql:/etc/postfix/mysql-virtual_sender.cf, permit_sasl_authenticated, reject_non_fqdn_sender, reject_unlisted_sender
smtpd_reject_unlisted_sender = no
smtpd_client_restrictions = check_client_access proxy:mysql:/etc/postfix/mysql-virtual_client.cf, permit_inet_interfaces, permit_mynetworks, permit_sasl_authenticated, check_client_access hash:/etc/postfix/rbl_override, permit_dnswl_client swl.spamhaus.org, permit_dnswl_client ip4.white.polspam.pl, permit_dnswl_client ip6.white.polspam.pl, reject_rbl_client spam.spamrats.com, reject_rbl_client b.barracudacentral.org, reject_rbl_client cbl.abuseat.org, reject_rbl_client bl.spameatingmonkey.net, reject_rbl_client all.s5h.net, reject_unauth_pipelining, permit
smtpd_etrn_restrictions = permit_mynetworks, reject
smtpd_data_restrictions = permit_mynetworks, reject_unauth_pipelining, reject_multi_recipient_bounce, permit
smtpd_client_message_rate_limit = 100
maildrop_destination_concurrency_limit = 1
maildrop_destination_recipient_limit = 1
virtual_transport = lmtp:unix:private/dovecot-lmtp
header_checks = regexp:/etc/postfix/header_checks
mime_header_checks = regexp:/etc/postfix/mime_header_checks
nested_header_checks = regexp:/etc/postfix/nested_header_checks
body_checks = regexp:/etc/postfix/body_checks
owner_request_special = no
smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
smtpd_tls_protocols = !SSLv2,!SSLv3
smtp_tls_protocols = !SSLv2,!SSLv3
smtpd_tls_exclude_ciphers = RC4, aNULL
smtp_tls_exclude_ciphers = RC4, aNULL
smtpd_tls_mandatory_ciphers = medium
tls_medium_cipherlist = ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:DHE-RSA-AES128-GCM-SHA256:DHE-RSA-AES256-GCM-SHA384:DHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA:ECDHE-RSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES256-SHA256:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:DES-CBC3-SHA
tls_preempt_cipherlist = yes
address_verify_negative_refresh_time = 60s
enable_original_recipient = no
sender_dependent_relayhost_maps = proxy:mysql:/etc/postfix/mysql-virtual_sender-relayhost.cf
smtp_sasl_password_maps = proxy:mysql:/etc/postfix/mysql-virtual_sender-relayauth.cf, texthash:/etc/postfix/sasl_passwd
smtp_sender_dependent_authentication = yes
smtp_sasl_auth_enable = yes
smtp_sasl_security_options = noanonymous, noplaintext
smtp_sasl_tls_security_options = noanonymous
authorized_flush_users =
authorized_mailq_users = nagios, icinga
smtpd_forbidden_commands = CONNECT,GET,POST,USER,PASS
address_verify_sender_ttl = 15686s
smtp_dns_support_level = dnssec
dovecot_destination_recipient_limit = 1
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_milters = inet:localhost:11332
non_smtpd_milters = inet:localhost:11332
milter_protocol = 6
milter_mail_macros = i {mail_addr} {client_addr} {client_name} {auth_authen}
milter_default_action = accept
message_size_limit = 0
我的主人.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) (no) (never) (100)
# ==========================================================================
# smtp inet n - y - - smtpd
127.0.0.1:smtp inet n - y - - smtpd
-o syslog_name=postfix/smtp-local
-o smtp_helo_name=localhost
-o myhostname=localhost
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
xx.xx.xx.x1:smtp inet n - y - - smtpd
-o syslog_name=postfix/smtp-d1
-o smtp_helo_name=domain1
-o myhostname=domain1
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
xx.xx.xx.x2:smtps inet n - y - - smtpd
-o syslog_name=postfix/smtp-d2
-o smtp_helo_name=domain2
-o myhostname=domain2
-o smtpd_tls_cert_file=/etc/domain2.crt
-o smtpd_tls_key_file=/etc/domain2.key
xx.xx.xx.x3:smtps inet n - y - - smtpd
-o syslog_name=postfix/smtp-d3
-o smtp_helo_name=domain3
-o myhostname=domain3
-o smtpd_tls_cert_file=/etc/domain3.crt
-o smtpd_tls_key_file=/etc/domain3.key
#smtp inet n - y - 1 postscreen
#smtpd pass - - y - - smtpd
#dnsblog unix - - y - 0 dnsblog
#tlsproxy unix - - y - 0 tlsproxy
#
127.0.0.1:submission inet n - y - - smtpd
-o syslog_name=postfix/submission
-o smtp_helo_name=localhost
-o smtp_bind_address=127.0.0.1
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
-o myhostname=localhost
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
xx.xx.xx.x1:submission inet n - y - - smtpd
-o syslog_name=postfix/submission
-o smtp_helo_name=domain1
-o smtp_bind_address=xx.xx.xx.x1
-o myhostname=domain1
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
xx.xx.xx.x2:submission inet n - y - - smtpd
-o syslog_name=postfix/submission
-o smtp_helo_name=domain2
-o smtp_bind_address=xx.xx.xx.x2
-o myhostname=domain2
-o smtpd_tls_cert_file=/etc/domain2.crt
-o smtpd_tls_key_file=/etc/domain2.key
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
xx.xx.xx.x3:submission inet n - y - - smtpd
-o syslog_name=postfix/submission
-o smtp_helo_name=domain3
-o smtp_bind_address=xx.xx.xx.x3
-o myhostname=domain3
-o smtpd_tls_cert_file=/etc/domain3.crt
-o smtpd_tls_key_file=/etc/domain3.key
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
# -o syslog_name=postfix/submission
# -o smtpd_tls_security_level=encrypt
# -o smtpd_sasl_auth_enable=yes
# -o smtpd_tls_auth_only=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 - y - - smtpd
## -o syslog_name=postfix/smtps
## -o smtpd_tls_wrappermode=yes
## -o smtpd_sasl_auth_enable=yes
## -o smtpd_client_restrictions=permit_sasl_authenticated,reject
# -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
127.0.0.1:smtps inet n - n - - smtpd
-o syslog_name=postfix/smtps
-o smtp_helo_name=localhost
-o myhostname=localhost
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
xx.xx.xx.x1:smtps inet n - n - - smtpd
-o syslog_name=postfix-d1/smtps
-o smtp_helo_name=domain1
-o myhostname=domain1
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
xx.xx.xx.x2:smtps inet n - n - - smtpd
-o syslog_name=postfix-d2/smtps
-o smtp_helo_name=domain2
-o myhostname=domain2
-o smtpd_tls_cert_file=/etc/domain2.crt
-o smtpd_tls_key_file=/etc/domain2.key
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
xx.xx.xx.x3:smtps inet n - n - - smtpd
-o syslog_name=postfix-d3/smtps
-o smtp_helo_name=domain3
-o myhostname=domain3
-o smtpd_tls_cert_file=/etc/domain3.crt
-o smtpd_tls_key_file=/etc/domain3.key
-o smtpd_tls_wrappermode=yes
-o smtpd_sasl_auth_enable=yes
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
domain1-out unix - - n - - smtp
-o smtp_bind_address=xx.xx.xx.x1
-o smtp_helo_name=domain1
-o syslog_name=postfix-domain1
-o smtpd_tls_cert_file=/etc/domain1.crt
-o smtpd_tls_key_file=/etc/domain1.key
domain2-out unix - - n - - smtp
-o smtp_bind_address=xx.xx.xx.x2
-o smtp_helo_name=domain2
-o syslog_name=postfix-domain2
-o smtpd_tls_cert_file=/etc/domain2.crt
-o smtpd_tls_key_file=/etc/domain2.key
domain3-out unix - - n - - smtp
-o smtp_bind_address=xx.xx.xx.x3
-o smtp_helo_name=domain3
-o syslog_name=postfix-domain3
-o smtpd_tls_cert_file=/etc/domain3.crt
-o smtpd_tls_key_file=/etc/domain3.key
#628 inet n - y - - qmqpd
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
qmgr unix n - n 300 1 qmgr
#qmgr unix n - n 300 1 oqmgr
tlsmgr unix - - y 1000? 1 tlsmgr
rewrite unix - - y - - trivial-rewrite
bounce unix - - y - 0 bounce
defer unix - - y - 0 bounce
trace unix - - y - 0 bounce
verify unix - - y - 1 verify
flush unix n - y 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - y - - smtp
relay unix - - y - - smtp
-o syslog_name=postfix/$service_name
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq unix n - y - - showq
error unix - - y - - error
retry unix - - y - - error
discard unix - - y - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - y - - lmtp
anvil unix - - y - 1 anvil
scache unix - - y - 1 scache
postlog unix-dgram n - n - 1 postlogd
#
# ====================================================================
# 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=DRXhu 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
# flags=DRX 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=FRX user=list argv=/usr/lib/mailman/bin/postfix-to-mailman.py ${nexthop} ${user}
dovecot unix - n n - - pipe
flags=DRhu user=vmail:vmail argv=/usr/lib/dovecot/deliver -f ${sender} -d ${user}@${nexthop}
當在 /var/log/mail.log 中啟動 postfix 時，有：
postfix/postfix-script[2714262]: starting the Postfix mail system
postfix/master[2714264]: warning: duplicate master.cf entry for service "xx.xx.xx.x2:smtps" ([xx.xx.xx.x2]:465) -- using the last ent
ry
postfix/master[2714264]: warning: duplicate master.cf entry for service "xx.xx.xx.x3:smtps" ([xx.xx.xx.x3]:465) -- using the last ent
ry
postfix/master[2714264]: daemon started -- version 3.5.6, configuration /etc/postfix
這個日誌對我來說很奇怪，因為連接埠 465 在每個網域上都工作正常。
為了進行測試，我使用其他伺服器和以下指令：
openssl s_client -starttls smtp -showcerts -connect domainX:25 -servername domainX
openssl s_client -starttls smtp -showcerts -connect domainX:587 -client -starttls
smtp -showcerts -connect domainX :587 -servername 4第465章
答案1
您的master.cf內容包含錯字。
看起來您打算smtpd在連接埠提交（587）上設定（伺服器）服務，在連接埠 smtps（465）上設定 smtpd，在連接埠 smtp（25）上設定 smtpd 以及smtp每個網域的（客戶端）傳輸。
但 的第一次出現xx.xx.xx.x2:smtps和 的第一次出現與xx.xx.xx.x3:smtps該方案不符。看來你打算寫smtp在那裡。每個的第二次出現看起來都像預期的那樣smtps（如 smtpd_tls_wrappermode 選項所證明）。
修復此問題並重新啟動 postfix 後，呼叫ss -tulpn以驗證 postfix 實際上正在偵聽哪些 IP/連接埠組合。我希望看到連接埠 25、連接埠 587 和連接埠 465 中的每一個都在四個 IPv4 位址上提供（包括環回）。
順便說一下，smtpd_*在服務上指定選項smtp是沒有效果的。您的網域*-out smtp（客戶端！）服務在交付時不提供憑證。
而且，整個努力似乎……很麻煩，卻沒有任何收穫。明明是一台伺服器，為什麼要裝成三台呢？透過在不同的地方接受傳入的郵件，只會使診斷變得更加困難。
答案2
透過 ISP 配置..
你可以更容易做到這一點..
在網站中建立一個「基本」郵件主機。 *（我將這個用於我的所有客戶的網路郵件。所以我建立了mail.my-hosting-domain.tld。
添加 LetsEncrypt 到它，以便您獲得正確的證書。現在新增一個新的郵件主機名稱。
LetsEncrypt 將產生一個多主機憑證。完畢。
當然，將所需的 DNS 記錄與此相符。任何客戶都可以前往 mail.there-domain.tld，postfix 會顯示憑證中所有正確的主機名稱。