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如何阻止 Postfix 发送垃圾邮件？

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如何阻止 Postfix 发送垃圾邮件？

我的 postfix 正在从[电子邮件保护]地址。这怎么可能呢？我如何只允许 www-data@localhost 发送，而 postfix 只允许从[电子邮件保护]到[电子邮件保护]（如我的别名列表一样）？

这是我的 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 = *** My main domain ***

    smtpd_banner = $myhostname ESMTP $mail_name (Debian/GNU)
    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 = *** My hostname ***
    alias_maps = hash:/etc/aliases
    alias_database = hash:/etc/aliases
    myorigin = $mydomain
    mydestination = $myhostname, localhost.$mydomain, $mydomain, localhost
    mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
    mailbox_size_limit = 0
    recipient_delimiter = +
    smtpd_sasl_auth_enable = yes
    smtpd_sasl_security_options = noanonymous noplaintext
    smtpd_recipient_restrictions = permit_mynetworks reject_unauth_destination permit_inet_interfaces
    smtpd_tls_security_level = may

    virtual_alias_domains = *** My aliases ***
    virtual_alias_maps = hash:/etc/postfix/virtual
    smtpd_tls_auth_only = yes


smtpd_client_restrictions = permit_mynetworks, reject
smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit
smtpd_data_restrictions = reject_unauth_pipelining
smtpd_end_of_data_restrictions = check_policy_service unix:private/policy
smtp_sasl_auth_enable = no
smtpd_sender_restrictions = permit_sasl_authenticated, permit_mynetworks, reject_non_fqdn_sender, reject_unknown_sender_domain, hash:/etc/postfix/sender_access, permit
smtpd_delay_reject = yes
smtpd_helo_required = yes
smtpd_helo_restrictions = permit_mynetworks, check_helo_access hash:/etc/postfix/sender_access, reject_non_fqdn_hostname, reject_invalid_hostname, permit
smtpd_recipient_restrictions = reject_unauth_pipelining, reject_unauth_destination, reject_non_fqdn_recipient, permit_mynetworks, permit_sasl_authenticated, check_sender_access hash:/etc/postfix/sender_access, reject_rbl_client relays.ordb.org, reject_rbl_client list.dsbl.org, reject_rbl_client sbl-xbl.spamhaus.org, check_policy_service unix:private/spfpolicy, check_policy_service inet:127.0.0.1:10023, permit
transport_maps = hash:/etc/postfix/transport

答案1

你有

smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_unauth_destination, permit

你需要那场决赛吗, permit？

看http://www.postfix.org/SMTPD_ACCESS_README.html#lists其中有

# Relay control (Postfix 2.10 and later): local clients and
# authenticated clients may specify any destination domain.
smtpd_relay_restrictions = permit_mynetworks, 
    permit_sasl_authenticated,
    reject_unauth_destination

答案2

看看正确设置relay_recipient_maps是否可以修复此问题。

我认为这就是问题所在……

您设置reject_unauth_destination是正确的，但服务器基本上没有明确说明“未授权目的地”实际上是什么。如果它不是您机器上的帐户或转发，则除非它是sasl身份验证或允许的网络机器，否则不应授权它进行中继。

垃圾邮件发送者会向您的机器发送伪造的邮件，而您的机器无法将这些邮件投递给不存在的帐户。由于无法判断这些邮件是否为“未经授权”的邮件，因此它会尝试将这些邮件视为合法的 SMTP 错误，而不是未经授权的邮件，因此会将错误发送回“发送方”MTA（该 MTA 是伪造的或配置错误的）。

在正确配置的邮件服务器上，延迟应该相当罕见。如果您觉得这样做是安全的，并且确定不会删除任何合法内容，请运行postsuper -d ALL deferred以删除队列中的所有延迟邮件。如果我是对的，队列不应该再像那样填满了。

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