Postfix、SPF 和 Perl：警告：在读取输入属性名称时，私有/策略上的输入过早结束

我遵循了本指南（http://www.thenoccave.com/2013/05/08/centos-6-postfix-spf-checking/），但出现以下错误maillog：

May  8 22:15:13 ip-172-31-15-65 postfix/smtpd[1999]: warning: premature end-of-input on private/policy while reading input attribute name
May  8 22:15:14 ip-172-31-15-65 postfix/spawn[2037]: warning: command /usr/bin/perl exit status 2
May  8 22:15:14 ip-172-31-15-65 postfix/smtpd[1999]: warning: premature end-of-input on private/policy while reading input attribute name
May  8 22:15:14 ip-172-31-15-65 postfix/smtpd[1999]: warning: problem talking to server private/policy: Connection reset by peer

这是一部分main.cf

smtpd_recipient_restrictions = reject_non_fqdn_sender,
  reject_non_fqdn_recipient,
  reject_unknown_recipient_domain,
  permit_sasl_authenticated,
  reject_unauth_destination,
  permit_inet_interfaces,
  check_policy_service unix:postgrey/socket,
  check_policy_service unix:private/policy policy_time_limit = 3600s

这是一部分master.cf

policy  unix  -       n       n       -       -       spawn user=nobody argv=/usr/bin/perl /usr/lib/postfix-policyd-spf-perl

我也试过

  check_policy_service unix:postgrey/socket,
  check_policy_service unix:private/policy,
  policy_time_limit = 3600s

这是完整的master.cf。

postfix check不报告任何错误。

有一个类似的问题，但它是针对 Debian 和 Python 的。

CentOS 6.6，postfix-policyd-spf-perl 2.01。