在发送 CRLF 之前，带有代理协议的 AWS NLB 后面的 Postfix 不会发送横幅

我已将我的邮件堆栈重新部署为 Kubernetes pod。此 pod 位于私有子网中的 EKS 集群上，位于 NLB 后面。Postfix 和 NLB 配置为使用代理协议 v2。

最初我在没有代理协议的情况下进行了此设置，并且 Postfix 端口按预期响应，在连接时立即发送 Postfix 横幅，但是 Postfix 无法正确识别向其发送邮件的远程服务器，并将所有内容标记为垃圾邮件。所以我决定走代理协议路线。

通过 telnet 连接时，连接打开，但 Postfix 不发送它的横幅。在发送 CRLF（按下回车键）之前不会发送横幅 - 您可以发送任何其他字符，并且在发送 CRLF 之前不会发生任何事情。这会影响 (587) 上的提交端口并中断客户端连接，因为 SMTP 协议声明接收服务器必须首先响应。

初始连接：

❯ telnet mx01.example.com 587
Trying x.x.x.x...
Connected to mx01.example.com.
Escape character is '^]'.

发送 CRLF 后：

❯ telnet mx01.example.com 587
Trying x.x.x.x...
Connected to mx01.example.com.
Escape character is '^]'.

220 mx01.example.com ESMTP Postfix (Ubuntu)
500 5.5.2 Error: bad syntax

这没有代理协议配置：

❯ telnet mx01.example.com 587
Trying x.x.x.x...
Connected to mx01.example.com.
Escape character is '^]'.
220 mx01.example.com ESMTP Postfix (Ubuntu)

版本：

操作系统：Ubuntu 20.10

后缀版本：3.5.6-1

后缀 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)   (no)    (never) (100)
# ==========================================================================
smtp      inet  n       -       y       -       1       postscreen
smtpd     pass  -       -       y       -       -       smtpd
dnsblog   unix  -       -       y       -       0       dnsblog
tlsproxy  unix  -       -       y       -       0       tlsproxy
submission inet n       -       -       -       -       smtpd
  -o syslog_name=postfix/submission
  -o smtpd_tls_security_level=encrypt
  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
  -o cleanup_service_name=header_cleanup
  -o smtpd_upstream_proxy_protocol=haproxy
#smtps     inet  n       -       y       -       -       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=$mua_sender_restrictions
#  -o smtpd_recipient_restrictions=
#  -o smtpd_relay_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
#628       inet  n       -       y       -       -       qmqpd
pickup    unix  n       -       y       60      1       pickup
cleanup   unix  n       -       y       -       0       cleanup
header_cleanup unix n   -       -       -       0       cleanup
 -o header_checks=regexp:/etc/postfix/submission_header_cleanup.cf
qmgr      unix  n       -       n       300     1       qmgr
#qmgr     unix  n       -       n       300     1       oqmgr
tlsmgr    unix  -       -       y       1000?   1       tlsmgr
rewrite   unix  -       -       y       -       -       trivial-rewrite
bounce    unix  -       -       y       -       0       bounce
defer     unix  -       -       y       -       0       bounce
trace     unix  -       -       y       -       0       bounce
verify    unix  -       -       y       -       1       verify
flush     unix  n       -       y       1000?   0       flush
proxymap  unix  -       -       n       -       -       proxymap
proxywrite unix -       -       n       -       1       proxymap
smtp      unix  -       -       y       -       -       smtp
relay     unix  -       -       y       -       -       smtp
        -o syslog_name=postfix/$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=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
#
# ====================================================================
#
# See the Postfix UUCP_README file for configuration details.
#
uucp      unix  -       n       n       -       -       pipe
  flags=Fqhu user=uucp argv=uux -r -n -z -a$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}