我正在尝试使用 Postfix 和 Dovecot 在 Ubuntu 16.04.5 LTS 上设置邮件服务器。
我可以毫无问题地发送电子邮件，从本地主机发送的邮件也可以进入收件箱。但是，从外部（例如 Gmail）发送的电子邮件没有显示。
serverfault 和其他网站上有很多类似的问题，但是我仍然无法让它工作。
我的main.cf：
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# TLS parameters
smtpd_tls_cert_file = /etc/letsencrypt/live/MYDOMAIN.FI/fullchain.pem
smtpd_tls_key_file =/etc/letsencrypt/live/MYDOMAIN.FI/privkey.pem
smtpd_use_tls = yes
smtpd_tls_security_level=may
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
smtpd_tls_protocols = !SSLv2, !SSLv3
# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.
smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = mail.MYDOMAIN.FI
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = $myhostname, localhost.$mydomain, localhost, $mydomain, mail.MYDOMAIN.FI, localhost.localdomain
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
home_mailbox = Maildir/
virtual_alias_maps = hash:/etc/postfix/virtual
smtpd_sasl_auth_enable = yes
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/dovecot-auth
smtpd_sasl_authenticated_header = yes
smtpd_sasl_security_options = noanonymous
smtpd_sasl_local_domain = $myhostname
broken_sasl_auth_clients = yes
smtpd_recipient_restrictions = reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_unauth_pipelining, permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination
smtpd_sender_restrictions = reject_unknown_sender_domain
mailbox_command = /usr/lib/dovecot/deliver -c /etc/dovecot/dovecot.conf -m "${EXTENSION}"
smtp_use_tls = yes
smtpd_tls_received_header = yes
smtpd_tls_mandatory_protocols = SSLv3, TLSv1
smtpd_tls_mandatory_ciphers = medium
smtpd_tls_auth_only = yes
tls_random_source = dev:/dev/urandom
如您所见，我使用了来自 letsencrypt 的 SSL 证书。
我已经用 MYDOMAIN.FI 替换了我的实际域名，以防我的配置中错误地留下一些可怕的漏洞。
输出sudo lsof -iTCP -sTCP:LISTEN -P：
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
systemd 1 root 29u IPv4 2041021 0t0 TCP *:143 (LISTEN)
systemd 1 root 44u IPv6 2041022 0t0 TCP *:143 (LISTEN)
systemd 1 root 56u IPv4 2041023 0t0 TCP *:993 (LISTEN)
systemd 1 root 59u IPv6 2041024 0t0 TCP *:993 (LISTEN)
sshd 1589 root 3u IPv4 14438 0t0 TCP *:22 (LISTEN)
sshd 1589 root 4u IPv6 14448 0t0 TCP *:22 (LISTEN)
mysqld 1870 mysql 22u IPv4 16248 0t0 TCP mail.MYDOMAIN.FI:330 6 (LISTEN)
apache2 1876 root 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 1876 root 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
miniserv. 2050 root 5u IPv4 16967 0t0 TCP *:10000 (LISTEN)
apache2 3762 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3762 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3763 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3763 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3766 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3766 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3767 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3767 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3771 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3771 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3842 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3842 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 3843 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 3843 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
apache2 4465 www-data 4u IPv6 16115 0t0 TCP *:80 (LISTEN)
apache2 4465 www-data 6u IPv6 16119 0t0 TCP *:443 (LISTEN)
master 20916 root 13u IPv4 2039338 0t0 TCP *:25 (LISTEN)
master 20916 root 14u IPv6 2039339 0t0 TCP *:25 (LISTEN)
master 20916 root 28u IPv4 2044183 0t0 TCP *:465 (LISTEN)
master 20916 root 111u IPv6 2044184 0t0 TCP *:465 (LISTEN)
master 20916 root 114u IPv4 2044888 0t0 TCP *:587 (LISTEN)
master 20916 root 115u IPv6 2044889 0t0 TCP *:587 (LISTEN)
dovecot 21229 root 3u IPv4 2041021 0t0 TCP *:143 (LISTEN)
dovecot 21229 root 4u IPv6 2041022 0t0 TCP *:143 (LISTEN)
dovecot 21229 root 5u IPv4 2041023 0t0 TCP *:993 (LISTEN)
dovecot 21229 root 6u IPv6 2041024 0t0 TCP *:993 (LISTEN)
它确实列出了端口 25 的命令“master” 而不是 “postfix”。不确定这是否相关。
我刚刚还注意到有 mysqld 命令正在监听mail.MYDOMAIN.FI:330。这正常吗？
输出netstat -tulpn：
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 1870/mysqld
tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN 20916/master
tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 1/init
tcp 0 0 0.0.0.0:10000 0.0.0.0:* LISTEN 2050/perl
tcp 0 0 0.0.0.0:465 0.0.0.0:* LISTEN 20916/master
tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1589/sshd
tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 20916/master
tcp 0 0 0.0.0.0:993 0.0.0.0:* LISTEN 1/init
tcp6 0 0 :::587 :::* LISTEN 20916/master
tcp6 0 0 :::143 :::* LISTEN 1/init
tcp6 0 0 :::80 :::* LISTEN 1876/apache2
tcp6 0 0 :::465 :::* LISTEN 20916/master
tcp6 0 0 :::22 :::* LISTEN 1589/sshd
tcp6 0 0 :::25 :::* LISTEN 20916/master
tcp6 0 0 :::443 :::* LISTEN 1876/apache2
tcp6 0 0 :::993 :::* LISTEN 1/init
udp 0 0 0.0.0.0:10000 0.0.0.0:* 2050/perl
udp 0 0 0.0.0.0:68 0.0.0.0:* 1195/dhclient
领域应该正确设置。我可以使用在线服务，例如https://www.adminkit.net/telnet.aspx和https://pentest-tools.com/network-vulnerability-scanning/tcp-port-scanner-online-nmap检查端口，一切连接正常。
/etc/dovecot.conf
disable_plaintext_auth = no
mail_privileged_group = mail
mail_location = mbox:~/mail:INBOX=/var/mail/%u
userdb {
driver = passwd
}
passdb {
args = %s
driver = pam
}
protocols = " imap"
service auth {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0660
user = postfix
}
}
ssl=required
ssl_cert = </etc/letsencrypt/live/MYDOMAIN.fi/fullchain.pem
ssl_key = </etc/letsencrypt/live/MYDOMAIN.fi/privkey.pem
log_path = /var/log/dovecot/dovecot.log
# Debug
mail_debug = yes
auth_verbose = yes
auth_debug = yes
auth_debug_passwords = yes
主配置文件：
# ==========================================================================
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (no) (never) (100)
# ==========================================================================
submission inet n - - - - smtpd -v
-o syslog_name=postfix/submission
-o smtpd_tls_wrappermode=no
-o smtpd_tls_security_level=encrypt
-o smtpd_sasl_auth_enable=yes
-o smtpd_recipient_restrictions=permit_mynetworks,permit_sasl_authenticated,reject
-o milter_macro_daemon_name=ORIGINATING
-o smtpd_sasl_type=dovecot
-o smtpd_sasl_path=private/auth
smtp inet n - y - - smtpd -v
smtps inet n - y - - smtpd -v
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}
启用详细功能后的一些日志输出：
Oct 30 11:21:08 mail postfix/smtpd[15895]: > mail-qt1-f180.google.com[209.85.160.180]: 250 DSN
Oct 30 11:21:08 mail postfix/smtpd[15895]: < mail-qt1-f180.google.com[209.85.160.180]: STARTTLS
Oct 30 11:21:08 mail postfix/smtpd[15895]: > mail-qt1-f180.google.com[209.85.160.180]: 220 2.0.0 Ready to start TLS
Oct 30 11:21:08 mail postfix/smtpd[15895]: send attr request = seed
Oct 30 11:21:08 mail postfix/smtpd[15895]: send attr size = 32
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: status
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: status
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute value: 0
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: seed
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: seed
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute value: 3dBahrjW0vbosyTKvktYBqwgAeKFMcaSFZXzLuCQJE8=
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: (list terminator)
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: (end)
Oct 30 11:21:08 mail postfix/smtpd[15895]: send attr request = tktkey
Oct 30 11:21:08 mail postfix/smtpd[15895]: send attr keyname = [data 0 bytes]
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: status
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: status
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute value: 0
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: keybuf
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: keybuf
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute value: dyOgaB79c3WwkEvn7j2vy4l+BbNCdTfeefaIo1tc0RCukA/4SsmzUQMfefep4DH4T15cOEPT6EcbQ8Bvs9otmDdVPIJ0zxeiQUZqefefeSiabN9hbAAAAAA==
Oct 30 11:21:08 mail postfix/smtpd[15895]: private/tlsmgr: wanted attribute: (list terminator)
Oct 30 11:21:08 mail postfix/smtpd[15895]: input attribute name: (end)
Oct 30 11:21:08 mail postfix/smtpd[15895]: xsasl_dovecot_server_create: SASL service=smtp, realm=mail.MYDOMAIN.fi
Oct 30 11:21:08 mail postfix/smtpd[15895]: name_mask: noanonymous
Oct 30 11:21:08 mail postfix/smtpd[15895]: xsasl_dovecot_server_connect: Connecting
Oct 30 11:21:08 mail postfix/smtpd[15895]: warning: SASL: Connect to private/dovecot-auth failed: Connection refused
Oct 30 11:21:08 mail postfix/smtpd[15895]: fatal: no SASL authentication mechanisms
答案1
1）Mysqld监听3306端口，所以必须安装数据库吗？应该不会干扰邮件服务。
2）监听 25 端口的 /master 进程是 Postfix 邮件传输代理。看起来正常
3）尝试使用以下方式在外部测试您的邮件服务器https://mxtoolbox.com/NetworkTools.aspx
进行 MX 检查，https://mxtoolbox.com/MXLookup.aspx（查看你的 DNS 是否配置正确）和 SMTP 测试https://mxtoolbox.com/diagnostic.aspx
4) 该消息warning: SASL: Connect to private/dovecot-auth failed: Connection refused指出 docecot ( /etc/dovecot/dovecot.conf ) 配置错误。您还需要在此处添加 SSL 证书 + 一些其他值得检查的设置。一个提示是添加 DEBUG 开关。
将 dovecot.conf 中的默认设置更改为有用的设置
#log_path = /var/log/dovecot/dovecot.log # Debug #mail_debug = yes # auth_verbose = yes #auth_debug = yes #auth_debug_passwords = yes在 /etc/postfix/master.cf 中，添加 debug/verbose 日志记录，如下所示
smtp inet n - n - - smtpd -v
答案2
你有：
smtpd_sender_restrictions = reject_unknown_sender_domain
smtpd_recipient_restrictions =
reject_unknown_sender_domain,
reject_unknown_recipient_domain,
reject_unauth_pipelining,
permit_mynetworks,
permit_sasl_authenticated,
reject_unauth_destination
由于这些服务器缺少结尾permit，因此只有经过mynetworksSASL 验证的用户才可以使用该服务器。此限制会影响所有邮件，包括以该服务器为最终目的地的邮件。这会导致错误fatal: no SASL authentication mechanisms。
如果你希望对 SASL 认证用户使用不同的设置，请启用提交。这是 SMTPd 在 TCP/587 上监听您自己用户的出站邮件的另一个实例。遵循Postfix 和 Dovecot SASL您将按照上述方法配置您的 Postfix（请参见使用 SASL 和 Postfix 提交端口）。