如何使用 dspam 作为具有虚拟域的 postfix 和 dovecot 之间的守护进程处理外部别名？

Question

对于使用 Postfix 2.9.6、DSPam 3.10.1 和 Dovecot 2.1.7 的传入邮件，我遇到了以下情况：

Incoming Mail -> SMTP -> LMTP -> DSpam (as daemon) -> LMTP -> Dovecot

我有带有虚拟邮箱的虚拟域。到目前为止一切正常。

指向外部域的（虚拟？）别名现在出现了问题。假设，我有以下虚拟域：

virtualdomain1.com
virtualdomain2.com

我正在为其处理邮件。服务器本身运行在

mydomain.com

如果我现在添加一个指向外部域的别名，例如：

alias@virtualdomain1.com -> user@externaldomain.com

然后（据我所知），DSPam 检查邮件，通过 LMTP 将其传递给 Dovecot，Dovecot 拒绝邮件，因为 user@externaldomain.com 是未知的（当然这是真的）。

那么如何正确设置以处理虚拟域的别名呢？如果可能，我还想检查虚拟别名的传入邮件。

发送到 alias@virtualdomain1.com 的传入消息的日志是：

postfix/smtpd[23910]: connect from xxx.anyhost.com[1.2.3.4]
postfix/smtpd[23910]: NOQUEUE: filter: RCPT from xxx.anyhost.com[1.2.3.4]: <alias@virtualdomain1.com>: Recipient address triggers FILTER lmtp:unix:/dspam/dspam.sock; from=<sender@anyhost.com> to=<alias@virtualdomain1.com> proto=ESMTP helo=<anyhost.com>
postfix/smtpd[23910]: D91D0771AF70: client=xxx.anyhost.com[1.2.3.4]
postfix/cleanup[23917]: D91D0771AF70: message-id=<550937C8.9050901@anyhost.com>
postfix/smtpd[23910]: disconnect from xxx.anyhost.com[1.2.3.4]
postfix/qmgr[23278]: D91D0771AF70: from=<sender@anyhost.com>, size=1030, nrcpt=1 (queue active)
dovecot: lmtp(23920): Debug: none: root=, index=, control=, inbox=, alt=
dovecot: lmtp(23920): Connect from local
dovecot: lmtp(23920): Debug: Loading modules from directory: /usr/lib/dovecot/modules
dovecot: lmtp(23920): Debug: Module loaded: /usr/lib/dovecot/modules/lib90_sieve_plugin.so
dovecot: auth-worker(23921): mysql(127.0.0.1): Connected to database postfixadmin
dspam[9421]: Got error 550 in response to RCPT TO: 550 5.1.1 <user@exampledomain.com> User doesn't exist: user@exampledomain.com#015
dovecot: auth-worker(23921): sql(user@exampledomain.com): unknown user
dovecot: lmtp(23920): Debug: auth input:
dovecot: lmtp(23920): Disconnect from local: Client quit (in RCPT TO)
postfix/lmtp[23918]: D91D0771AF70: to=<user@exampledomain.com>, orig_to=<alias@virtualdomain1.com>, relay=mail.mydomain.com[/dspam/dspam.sock], delay=0.98, delays=0.47/0.01/0/0.5, dsn=5.3.0, status=bounced (host mail.mydomain.com[/dspam/dspam.sock] said: 530 5.3.0 <user@exampledomain.com> Fatal: 550 5.1.1 <user@exampledomain.com> User doesn't exist: user@exampledomain.com (in reply to end of DATA command))
postfix/cleanup[23917]: 149CB771AF72: message-id=<20150318083110.149CB771AF72@mail.mydomain.com>
postfix/bounce[23923]: D91D0771AF70: sender non-delivery notification: 149CB771AF72
postfix/qmgr[23278]: 149CB771AF72: from=<>, size=3182, nrcpt=1 (queue active)
postfix/qmgr[23278]: D91D0771AF70: removed
postfix/smtp[23925]: 149CB771AF72: to=<sender@anyhost.com>, relay=mx.mydomain.com[1.2.3.5]:25, delay=3.9, delays=0.26/0.01/0.09/3.6, dsn=2.0.0, status=sent (250 OK id=1YY9Ne-0007eJ-Hp)
postfix/qmgr[23278]: 149CB771AF72: removed

后缀 main.cf: smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU) biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

readme_directory = no

# BECAUSE we use Dovecot for authentication we also use its certificates
smtpd_tls_cert_file=/etc/dovecot/dovecot.pem
smtpd_tls_key_file=/etc/dovecot/private/dovecot.pem
smtpd_use_tls=yes
smtpd_tls_auth_only = yes

#Handing off local delivery to Dovecot's LMTP, and telling it where to store mail
virtual_transport = lmtp:unix:private/dovecot-lmtp

#Virtual domains, users, and aliases
virtual_mailbox_domains = proxy:mysql:$config_directory/mysql_virtual_domains_maps.cf
virtual_mailbox_maps =
    proxy:mysql:$config_directory/mysql_virtual_mailbox_maps.cf,
    proxy:mysql:$config_directory/mysql_virtual_alias_domain_mailbox_maps.cf,
    proxy:mysql:$config_directory/mysql_virtual_alias_domain_catchall_maps.cf
virtual_alias_maps =
    proxy:mysql:$config_directory/mysql_virtual_alias_maps.cf,
    proxy:mysql:$config_directory/mysql_virtual_alias_domain_maps.cf
virtual_mailbox_limit = proxy:mysql:$config_directory/mysql_virtual_mailbox_limit_maps.cf

myhostname = mail.me.com
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
myorigin = /etc/mailname
mydestination = localhost, $myhostname
relayhost =
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 1000000000
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all

#Enabling SMTP for authenticated users, and handing off authentication to Dovecot
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes

smtpd_recipient_restrictions =
        permit_sasl_authenticated,
        permit_mynetworks,
        reject_unauth_destination,
        check_recipient_access pcre:/etc/postfix/dspam_filter_access,
        permit

dspam_filter_access 文件：

/./  FILTER lmtp:unix:/dspam/dspam.sock

最后一点：如果我评论这一行

#check_recipient_access pcre:/etc/postfix/dspam_filter_access,

一切正常，但当然没有垃圾邮件检查。

Answer 1

在您当前的上述设置中，dovecot 和 dspam 都无法将您的电子邮件重新路由到正确的目的地。特别是对于 dovecot，它只能接受基于域配置的电子邮件。

解决方案是更改您的dspam设置，在扫描后将电子邮件发送回 postfix ，而不是将其发送到 dovecot。通过此设置，扫描后 postfix 路由引擎将重新路由您的电子邮件

• 到外部邮件服务器，如果收件人地址指向外部域
• 到 dovecot，如果收件人地址与您的虚拟域匹配

换句话说

[ Outside ] --smtp--> [ Postfix ] --lmtp--> [ dspam ] --smtp--> [ postfix ] --> dovecot (if localdomain) or another mail server (if external domain)

您可以像本教程中的 dspam 设置一样配置它。步骤总结

1. 在 master.cf 中添加第二个后缀 smtpd 监听器，例如 localhost:10026
2. 您可以使用 content_filter 参数，而不是使用dspam_filter_access将电子邮件发送到 dspam
3. 将DSPAM中Delivery{Host, Port, Proto}的配置更改为postfix第二个smtpd
4. 禁用地址映射 ( no_address_mappings) content_filter 和第二个 smtpd 中的另一个限制