我在使用 Postfix 时遇到了问题。最近我们收到的邮件带有格式错误的“发件人：”标头，如下所示：
From: "Name Surname <[email protected]>" <[email protected]>
From: "[email protected]" <[email protected]>
最终得到了基于 PCRE 标头检查的解决方案，使用以下两个正则表达式：
/^From:.+(".+<(.*@+.*)>").*<((?!\2).*)>$/ REJECT
/^From:.+("([^<>]*@+[^<>]*)").*<((?!\2).*)>$/ REJECT
完毕
postmap /etc/postfix/header_checks
并重新加载后缀。
看起来运行正常，并且 POstfix 显然可以毫无问题地处理 PCRE：
postmap -q 'From: "Name Surname <[email protected]>" <[email protected]>' pcre:/etc/postfix/header_checks
REJECT
postmap -q 'From: "[email protected]" <[email protected]>' pcre:/etc/postfix/header_checks
REJECT
但实际使用中邮件并没有被拦截。日志中有以下（重复的）错误：
Nov 22 10:52:19 mx1 postfix/cleanup[32087]: warning: regexp map /etc/postfix/header_checks, line 497: Invalid preceding regular expression
Nov 22 10:52:19 mx1 postfix/cleanup[32087]: warning: regexp map /etc/postfix/header_checks, line 498: Invalid preceding regular expression
/etc/postfix/header_checks文件内容如下（前496行是注释）：
/^From:.+(".+<(.*@+.*)>").*<((?!\2).*)>$/ REJECT
/^From:.+("([^<>]*@+[^<>]*)").*<((?!\2).*)>$/ REJECT
/^Subject:/ WARN
附加信息：
- There are no receive_override_options: the file is used as the subject are correctly logged in logfile (last line). And the errors too shows the file is handled by postfix.
- Tested the two regexp with multiple online services and they seems correct: also the postmap -q tests shows they are working correctly.
- Postfix 2.10.1 and PCRE 8.32 on a CentOS 7.7
任何想法？