Postfix+Dovecot邮件服务器外网无法发送邮件的问题求助

我最近在VPS上搭建了Postfix+Dovecot邮件服务器，在家用网络环境下（该网段已经配置到mynetworks里），收发邮件都正常。但一旦离开家在外网环境，只能接收邮件，没法发送——这完全不是我想要的效果，毕竟在外网时才更需要发邮件。

下面是我的配置文件，麻烦大家帮忙看看哪里出问题了：

main.cf配置 #

# 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 (Ubuntu)

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 = no

# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2

#Mail filter
#milter_default_action = accept
#milter_protocol = 6
#smtpd_milters = unix:/var/run/clamav/clamav-milter
#non_smtpd_milters = unix:/var/run/clamav/clamav-milter

# TLS parameters
smtpd_tls_cert_file=/etc/letsencrypt/live/mail.myserver.dev/fullchain.pem
smtpd_tls_key_file=/etc/letsencrypt/live/mail.myserver.dev/privkey.pem
smtpd_tls_security_level=encrypt
smtpd_use_tls = yes
smtpd_tls_auth_only = yes

smtp_tls_CApath=/etc/ssl/certs
smtp_tls_security_level=encrypt
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

smtpd_relay_restrictions = permit_sasl_authenticated, reject_unauth_destination

smtpd_recipient_restrictions =
permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination

mydomain = myserver.dev
myhostname = $mydomain

alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases

myorigin = /etc/mailname

mydestination = localhost.localdomain localhost

relayhost =

mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 123.456.789.159/32

mailbox_size_limit = 0

recipient_delimiter = +

inet_interfaces = all
inet_protocols = all

virtual_mailbox_domains = myserver.dev
virtual_mailbox_maps = hash:/etc/postfix/vmailbox
virtual_mailbox_base = /var/vmail
virtual_uid_maps = hash:/etc/postfix/virtual_uid
virtual_gid_maps = hash:/etc/postfix/virtual_gid

smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_sasl_tls_security_options = noanonymous

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_tls_security_options = noanonymous
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth

smtpd_client_connection_count_limit = 10
smtpd_client_connection_rate_limit = 30
smtpd_error_sleep_time = 1s
smtpd_soft_error_limit = 10
smtpd_hard_error_limit = 20

master.cf配置 #

smtp      inet  n       -       y       -       -       smtpd
#smtp      inet  n       -       y       -       1       postscreen
#smtpd     pass  -       -       y       -       -       smtpd
#dnsblog   unix  -       -       y       -       0       dnsblog
#tlsproxy  unix  -       -       y       -       0       tlsproxy

submission inet n - n - - smtpd
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_sasl_type=dovecot
-o smtpd_sasl_path=private/auth
-o smtpd_sasl_security_options=noanonymous
-o smtpd_sasl_local_domain=$myhostname
-o smtpd_client_restrictions=permit_sasl_authenticated,reject
-o smtpd_sender_login_maps=hash:/etc/postfix/virtual
-o smtpd_sender_restrictions=reject_sender_login_mismatch
-o smtpd_recipient_restrictions=reject_non_fqdn_recipient,reject_unknown_recipient_domain,permit_sasl_authenticated,reject

#submission inet n       -       y       -       -       smtpd

错误日志 #

之前遇到的错误：

May 26 11:57:36 vmi1240278 postfix/smtpd[1164363]: connect from unknown[XX.XXX.XX.XX]
May 26 11:57:37 vmi1240278 postfix/smtpd[1164363]: NOQUEUE: reject: RCPT from unknown[XX.XXX.XX.XX]: 554 5.7.1 <mymail@gmail.com>: Relay access denied; from=<me@myserver.dev> to=<mymail@gmail.com> proto=ESMTP helo=<smtpclient.apple>
May 26 11:57:37 vmi1240278 postfix/smtpd[1164363]: disconnect from unknown[XX.XXX.XX.XX] ehlo=2 starttls=1 mail=1 rcpt=0/1 quit=1 commands=5/6

现在修改了一些配置（具体改了啥我记不清了），出现了新错误：

May 26 16:28:33 vmi1240278 postfix/smtpd[1177893]: connect from unknown[XX.XXX.XX.XX]
May 26 16:28:33 vmi1240278 postfix/smtpd[1177893]: NOQUEUE: reject: RCPT from unknown[XX.XXX.XX.XX]: 554 5.7.1 <unknown[XX.XXX.XX.XX]>: Client host rejected: Access denied; from=<me@myserver.dev> to=<mymail@gmail.com> proto=ESMTP helo=<smtpclient.apple>
May 26 16:28:33 vmi1240278 postfix/smtpd[1177893]: disconnect from unknown[XX.XXX.XX.XX] ehlo=2 starttls=1 mail=1 rcpt=0/1 quit=1 commands=5/6

额外信息 #

用邮件应用的连接检查工具看到：

• SMTP：已连接，无需验证
• IMAP：已连接并验证

对比Gmail的配置，它的SMTP和IMAP都能正常完成验证。

麻烦各位大佬帮忙看看问题出在哪，感谢！

备注：内容来源于stack exchange，提问作者Tsetsi