Postfix 不允许端口 25 的外部连接

Question

我已经安装了 postfix，但有一段时间遇到问题。

我可以连接到本地主机上的端口 25，但是当我从外部计算机远程登录端口 25 时，连接似乎已建立但随后挂断了。

我收到回复：

421 Cannot connect to SMTP server xx.xxx.xx.xxx (xx.xx.xx.xxx:25), connect error 10061 Connection closed by foreign host.

我已 inet_interfaces 设置为全部。

main.cf

soft_bounce = no
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
myhostname = mydomain.com
mydomain = mydomain.com
myorigin = $myhostname
inet_interfaces = all
inet_protocols = all
mydestination = $myhostname, localhost.$mydomain, localhost
unknown_local_recipient_reject_code = 550
mynetworks = 168.100.189.0/28, 127.0.0.0/8
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
home_mailbox = Maildir/


debug_peer_level = 2
debugger_command =
     PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
     ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.10.1/samples
readme_directory = /usr/share/doc/postfix-2.10.1/README_FILES
smtpd_sasl_auth_enable = yes
broken_sasl_auth_clients = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_security_options = noanonymous

master.cf

smtp      inet  n       -       n       -       -       smtpd
submission inet n       -       n       -       -       smtpd
  -o syslog_name=postfix/submission
smtps     inet  n       -       n       -       -       smtpd
pickup    unix  n       -       n       60      1       pickup
cleanup   unix  n       -       n       -       0       cleanup
qmgr      unix  n       -       n       300     1       qmgr
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
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

netstat -plnt | grep 25

tcp        0      0 0.0.0.0:25              0.0.0.0:*               LISTEN      10742/master
tcp6       0      0 :::25                   :::*                    LISTEN      10742/master

Answer 1

到 smtp 端口的传入连接可能被防火墙阻止。

您可以尝试使用 tcptraceoute 等工具来定位此类防火墙。

Postfix 不允许端口 25 的外部连接

Postfix won't allow external connections for port 25

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