我已经在 ServerFault 上发布了这个问题，但它与这个网站相关，所以我将它复制到这里，因为我很绝望。
我的 Postfix 配置有几个问题。首先从这个问题开始：在 Postfix 日志中，Postfix 尝试连接 (SMTP)example.org而不是mailer.example.org。example.org是另一台计算机。
注意：我example.org用我拥有的域名替换了以下内容。example.org（运行 Web 服务器的计算机）和mailer.example.org（运行 Postfix 的计算机）的 DNS 解析都是正确的。
尝试发送电子邮件的测试：
ubuntu@mailer:~$ telnet localhost 25
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
220 mailer.example.org ESMTP Postfix (Ubuntu)
ehlo mailer.example.org
250-mailer.example.org
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-STARTTLS
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
mail from: <[email protected]>
250 2.1.0 Ok
rcpt to: <[email protected]>
250 2.1.5 Ok
data
354 End data with <CR><LF>.<CR><LF>
asdfasdf
.
250 2.0.0 Ok: queued as 3AB5A41927
/var/log/mail.log：
Sep 6 20:10:15 mailer postfix/smtpd[2785]: connect from localhost[127.0.0.1]
Sep 6 20:10:23 mailer postfix/smtp[2779]: connect to example.org[54.229.20.238]:25: Connection timed out
Sep 6 20:10:23 mailer postfix/smtp[2779]: 253C641852: to=<[email protected]>, relay=none, delay=1059, delays=1029/0.02/30/0, dsn=4.4.1, status=deferred (connect to example.org[54.229.20.238]:25: Connection timed out)
Sep 6 20:10:40 mailer postfix/smtpd[2785]: 3AB5A41927: client=localhost[127.0.0.1]
Sep 6 20:10:48 mailer postfix/cleanup[2789]: 3AB5A41927: message-id=<[email protected]>
Sep 6 20:10:48 mailer postfix/qmgr[2776]: 3AB5A41927: from=<[email protected]>, size=422, nrcpt=1 (queue active)
Sep 6 20:10:50 mailer postfix/smtpd[2785]: disconnect from localhost[127.0.0.1]
postconf-n：
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
config_directory = /etc/postfix
inet_interfaces = all
local_recipient_maps =
mailbox_size_limit = 0
mydestination =
myhostname = mailer.example.org
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = $mydomain
readme_directory = no
recipient_delimiter = +
relayhost =
smtp_tls_session_cache_database = btree:${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 = mysql:/etc/postfix/mysql_virtual_alias_maps.cf
virtual_gid_maps = static:5000
virtual_mailbox_base = /mnt/vmail
virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf
virtual_mailbox_limit = 51200000
virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf
virtual_minimum_uid = 5000
virtual_transport = virtual
virtual_uid_maps = static:5000
答案1
您应该检查 postfix 所见的 example.org 的 DNS 记录。
dig MX example.com
DNS 设置/可见性可能与您想象的不同。