用于基于别名的转发的简单 SMTP 服务器

Question

我正在寻找仅用于转发几个电子邮件地址的 SMTP 服务器。两个要求：

1. 在 Ubuntu 上易于安装和配置。
2. 具有易于自动添加的别名文件。理想情况下，它将是一个文本文件，由“foo@myserver.com mrfoo@gmail.com”之类的行组成。
3. （理想情况下）可以轻松配置为仅接受来自特定主机的邮件。

我一直在尝试 Postfix，但我陷入了诸如Recipient address rejected: User unknown in virtual alias table和 之类的错误消息中Recipient address rejected: User unknown in local recipient table。所以我想知道是否有更简单的解决方案。

Answer 1

1. 使用后缀

   在 ubuntu 上，执行以下操作

   apt-get install postfix
   

   我正在对我的 vps 电子邮件设置做完全相同的事情。查看我的博客文章Tiny VPS Postfix。我复制下面的例子

   /etc/postfix/main.cf

   # 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
   
   # 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.
   
   myhostname = <YOUR HOSTNAME>
   alias_maps = hash:/etc/aliases
   alias_database = hash:/etc/aliases
   myorigin = /etc/mailname
   mydestination = <YOUR DOMAIN NAME>, localhost.domain, localhost
   relayhost =
   mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
   mailbox_command = procmail -a "$EXTENSION"
   mailbox_size_limit = 0
   recipient_delimiter = +
   inet_interfaces = all
   
   smtpd_recipient_restrictions =
       permit_mynetworks,
       permit_sasl_authenticated,
       reject_invalid_hostname,
       reject_non_fqdn_hostname,
       reject_non_fqdn_sender,
       reject_non_fqdn_recipient,
       reject_unknown_recipient_domain,
       reject_unlisted_recipient,
       reject_unauth_destination,
       reject_rbl_client cbl.abuseat.org,
       reject_rbl_client bl.spamcop.net,
       reject_rbl_client relays.mail-abuse.org,
       reject_rbl_client dnsbl.proxybl.org,
       reject_rbl_client truncate.gbudb.net,
       reject_rbl_client dnsbl.njabl.org,
       permit
   

   记住要改变<YOUR HOSTNAME>和<YOUR DOMAIN NAME>

2. 别名文件

   您的/etc/aliases文件应如下所示

   foo: mrfoo@gmail.com
   bar: mrbar@gmail.com
   

   左侧不应有域名，只有用户名。该域由您的 postfix 配置控制。然后执行以下操作

   cd /etc
   postalias aliases
   service postfix restart
   

3. 单主机限制

   为了只允许来自单个（或几个）主机的电子邮件，我将使用一种非常懒惰的方法来做到这一点。

   假设允许传入主机的IP有IP 192.168.1.100，将其添加到mynetworks

   mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128 192.168.1.100
   

   更改smtpd_recipient_restrictions为以下

   smtpd_recipient_restrictions =
       permit_mynetworks,
       reject_unlisted_recipient
   

   Postfix 仅（且始终）接受来自 中列出的主机的电子邮件mynetworks。并拒绝其他一切。

4. DNS配置

   记得设置MX记录和spf记录。