我正在使用虚拟服务器设置网络。我使用 Windows Server 2016 作为我的 DHCP 和 DNS 服务器，它上面也有 Active Directory。我还使用 Ubuntu 18.04 作为我的网络 (www) 和网络邮件服务器。所以我已经安装了 dovecot、postfix 并且我正在使用 squirrelmail。我的域名是 arm.com，而我的 ubuntu 服务器，即邮件服务器（如前所述）是 ubuntusrv.arm.com。我已将我的网络邮件设置为 webmail.arm.com。Ubuntu 服务器的 IP 地址为 192.168.10.3，Windows 服务器的 IP 地址为 192.168.10.10。
我可以通过浏览器（在我域中的客户端 PC 上）访问我的网络邮件，但是当我尝试登录时，我在 mail.err 中收到这些消息：
May 8 23:29:38 ubuntusrv dovecot: auth: Error: LDAP: Can't connect to server: ubuntusrv.arm.com:389
May 8 23:29:38 ubuntusrv dovecot: auth-worker(2848): Error: LDAP: Can't connect to server: ubuntusrv.arm.com:389
May 8 23:29:39 ubuntusrv dovecot: auth-worker(2848): Error: pam(klijent1@arm.com,127.0.0.1,<3EXMsSmlUu1/AAAB>): pam_acct_mgmt() failed: Permission denied
May 8 23:29:39 ubuntusrv dovecot: auth: Error: LDAP: Can't connect to server: ubuntusrv.arm.com:389
和 mail.log 中的相同消息加上这个：
May 8 23:29:41 ubuntusrv dovecot: imap-login: Aborted login (auth failed, 1 attempts in 3 secs): user=<klijent1@arm.com>, method=PLAIN, rip=127.0.0.1, lip=127.0.0.1, secured, session=<3EXMsSmlUu1/AAAB>
这是我的后缀 main.cf 文件：
# 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 $mail_name (Ubuntu)
biff = no
# appending .domain is the MUA's job.
append_dot_mydomain = no
# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h
readme_directory = no
# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2
# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache
# 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
smtpd_sasl_auth_enable = yes
myhostname = empa-VirtualBox
alias_maps = ldap:/etc/postfix/asap/virtual_group_maps.cf, hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = webmail.arm.com, localhost.localdomain, localhost, arm.com
relayhost =
mynetworks = 192.168.10.0/24, 127.0.0.1/8 0.0.0.0/0
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all
dovecot_destination_recipient_limit = 1
virtual_alias_maps = proxy:ldap:/etc/postfix/asap/virtual_group_maps.cf
sender_bcc_maps =
recipient_bcc_maps =
relay_domains =
relay_recipient_maps =
sender_dependent_relayhost_maps =
smtpd_sasl_local_domain = arm.com
virtual_mailbox_domains = arm.com
virtual_transport = dovecot
transport_maps = hash:/etc/postfix/transport
smtpd_sender_login_maps = proxy:ldap:/etc/postfix/asap/sender_login_maps.cf
virtual_mailbox_maps = proxy:ldap:/etc/postfix/asap/virtual_mailbox_maps.cf
virtual_mailbox_base = /var/vmail/
virtual_uid_maps = static:1002
virtual_gid_maps = static:8
这是我的 dovecot.conf 文件：
dict {
#quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
#expire = sqlite:/etc/dovecot/dovecot-dict-sql.conf.ext
}
!include conf.d/*.conf
plugin {
quota_rule = *:storage=1G
}
mail_uid = 1000
mail_gid = 1000
first_valid_uid = 1000
last_valid_uid = 1000
postmaster_address = klijent1@arm.com
userdb {
driver = ldap
args = /etc/dovecot/dovecot-ldap.conf.ext
}
passdb {
driver = ldap
args = /etc/dovecot/dovecot-ldap.conf.ext
}
我是计算机科学和软件工程专业的学生，在计算机网络管理方面我是初学者。
谢谢您的帮助！