Dovecot-imap-login SSL_accept() 失败

Question

今天我按照教程配置了 Postfix、Dovecot 和 MySQLhttps://www.digitalocean.com/community/tutorials/how-to-configure-a-mail-server-using-postfix-dovecot-mysql-and-spamassassin

实际鸽舍设置：

root@cermofi-lab:~# dovecot -n
# 2.3.16 (7e2e900c1a): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.16 (09c29328)
# OS: Linux 5.15.0-92-generic x86_64 Ubuntu 22.04.3 LTS ext4
# Hostname: cermofi-lab
auth_mechanisms = plain login
mail_location = maildir:/var/mail/vhosts/%d/%n
mail_privileged_group = mail
namespace inbox {
  inbox = yes
  location = 
  mailbox Drafts {
    special_use = \Drafts
  }
  mailbox Junk {
    special_use = \Junk
  }
  mailbox Sent {
    special_use = \Sent
  }
  mailbox "Sent Messages" {
    special_use = \Sent
  }
  mailbox Trash {
    special_use = \Trash
  }
  prefix = 
}
passdb {
  args = /etc/dovecot/dovecot-sql.conf.ext
  driver = sql
}
protocols = imap lmtp
service auth-worker {
  user = vmail
}
service auth {
  unix_listener /var/spool/postfix/private/auth {
    group = postfix
    mode = 0666
    user = postfix
  }
  unix_listener auth-userdb {
    mode = 0600
    user = vmail
  }
  user = dovecot
}
service imap-login {
  inet_listener imap {
    port = 0
  }
}
service lmtp {
  unix_listener /var/spool/postfix/private/dovecot-lmtp {
    group = postfix
    mode = 0600
    user = postfix
  }
}
ssl = required
ssl_cert = </etc/letsencrypt/live/cermofi.cz/fullchain.pem
ssl_client_ca_dir = /etc/ssl/certs
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
userdb {
  args = uid=vmail gid=vmail home=/var/mail/vhosts/%d/%n
  driver = static
}

实际的 Postfix 设置：

root@cermofi-lab:~# postconf -n
alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases
append_dot_mydomain = no
biff = no
compatibility_level = 3.6
inet_interfaces = all
inet_protocols = all
mailbox_size_limit = 0
mydestination = localhost
myhostname = cermofi.cz
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
myorigin = /etc/mailname
readme_directory = no
recipient_delimiter = +
relayhost =
smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
smtpd_recipient_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_unauth_destination
smtpd_sasl_auth_enable = yes
smtpd_sasl_path = private/auth
smtpd_sasl_type = dovecot
smtpd_tls_cert_file = /etc/letsencrypt/live/cermofi.cz/fullchain.pem
smtpd_tls_key_file = /etc/letsencrypt/live/cermofi.cz/privkey.pem
smtpd_tls_loglevel = 3
smtpd_use_tls = yes
virtual_alias_maps = mysql:/etc/postfix/mysql-virtual-alias-maps.cf
virtual_mailbox_domains = mysql:/etc/postfix/mysql-virtual-mailbox-domains.cf
virtual_mailbox_maps = mysql:/etc/postfix/mysql-virtual-mailbox-maps.cf
virtual_transport = lmtp:unix:private/dovecot-lmtp

通过以下方式发送电子邮件SMTP（telnet 本地主机 25）成功了。但是当我尝试通过 TLS 发送它时（telnet 中的命令 starttls 返回“外部主机关闭连接”），它失败了。此外，当我尝试连接到 dovecot（telnet localhost 993）时，我收到与 TLS 上相同的错误消息。

Mail.err 为空。Mail.log：

Jan 30 17:29:45 cermofi-lab dovecot: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:0A00010B:SSL routines::wrong version number (no auth attempts in 1 secs): user=<>, rip=127.0.0.1, lip=127.0.0.1, TLS handshaking: SSL_accept() failed: error:0A00010B:SSL routines::wrong version number, session=<kkgxRSwQwsx/AAAB>

和

Jan 30 17:37:05 cermofi-lab postfix/smtpd[41027]: warning: TLS library problem: error:0A00010B:SSL routines::wrong version number:../ssl/record/ssl3_record.c:354:
Jan 30 17:37:05 cermofi-lab postfix/smtpd[41027]: lost connection after STARTTLS from localhost[127.0.0.1]

我的证书似乎没有问题：（openssl s_client -showcerts -connect cermofi.cz:993 -servername cermofi.cz 的输出）

    Start Time: 1706632917
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
    Max Early Data: 0
---
read R BLOCK
* OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ AUTH=PLAIN AUTH=LOGIN] Dovecot (Ubuntu) ready.

知道为什么 TLS 会失败吗？谢谢。