我能够配置 Postfix 使用 Google 的重发功能发送外部电子邮件，但这不是我想要的。我的意思是，我想通过自己的域发送邮件。
Postfix 已配置，它可以接收来自外部域的电子邮件。
但是我想发送外部邮件而不使用 Google 或其他中继。我该怎么做？配置是什么？
我的内部电子邮件是：[电子邮件保护]
版本：Ubuntu 17.10 (Artful Aardvark)；Postfix 3.2.3
以下是我的设置；
The ports 25 and 587 are open in GCP where postfix was configured
There is an linux user commercial name created where postfix was configured
MX and A DNS were setup and below you can see report yielded from dig linux command:
以下是我的额外设置；
something.io. 59 IN MX 10 mail.something.io.
mail.something.io. 59 IN A <SOMETHING IP ADDRESS>
$ dig MX something.io
; <<>> DiG 9.10.3-P4-Ubuntu <<>> MX something.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 19811
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;something.io. IN MX
;; ANSWER SECTION:
something.io. 39 IN MX 10 mail.something.io.
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Mon Nov 27 09:48:15 -02 2017
;; MSG SIZE rcvd: 59
$ dig A mail.something.io
; <<>> DiG 9.10.3-P4-Ubuntu <<>> A mail.something.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9197
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;mail.something.io. IN A
;; ANSWER SECTION:
mail.something.io. 47 IN A 35.188.104.163
;; Query time: 0 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Mon Nov 27 09:48:22 -02 2017
;; MSG SIZE rcvd: 59
$ sudo postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
compatibility_level = 2
home_mailbox = Maildir/
inet_interfaces = all
inet_protocols = all
mailbox_size_limit = 0
mydestination = $myhostname localhost.$mydomain localhost
myhostname = something.io
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
smtpd_tls_cert_file = /etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file = /etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtpd_use_tls = yes
virtual_alias_maps = hash:/etc/postfix/virtual
$ sudo postconf -M
smtp inet n - y - - smtpd
submission inet n - y - - smtpd
pickup unix n - y 60 1 pickup
cleanup unix n - y - 0 cleanup
qmgr unix n - n 300 1 qmgr
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
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
maildrop unix - n n - - pipe flags=DRhu user=vmail argv=/usr/bin/maildrop -d ${recipient}
uucp unix - n n - - pipe flags=Fqhu user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
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}
发送外部邮件的命令：
echo "Body-Test" | mail -s "Subject-Test" [email protected]
$ mailq
8318C43C73 447 Sun Nov 26 16:29:01 [email protected]
(connect to mx2.hotmail.com[65.55.37.104]:25: Connection timed out)
[email protected]
我想发送外部邮件，而不使用 Google 或其他中继。我该怎么做？配置是什么？
能不能请你检查一下，并指导我打开 postfix 以通过我自己的域发送外部邮件？谢谢
答案1
(connect to mx2.hotmail.com[65.55.37.104]:25: Connection timed out)
这表明您的配置可能没有任何问题，但您的服务器所处的连接不允许使用端口25进行传出连接，而这是将电子邮件直接发送到接收 MTA 所必需的。您之前使用 Google 重新传输的配置可能使用了提交端口587或465（对于 TLS）。
这种限制在不用于托管电子邮件服务器的线路上很常见。这是一种防止垃圾邮件从受感染的工作站发出的常见做法。询问您的 ISP 是否可以删除此限制或使用提交使用网络外部的中间 MTA。