NAME

       MIMEHeader - perform regexp tests against MIME headers

SYNOPSIS

         loadplugin    Mail::SpamAssassin::Plugin::MIMEHeader
         mimeheader    NAME_OF_RULE    Content-Id =~ /foo/

DESCRIPTION

       This plugin allows regexp rules to be written against MIME headers in the message.

RULE DEFINITIONS AND PRIVILEGED SETTINGS

       mimeheader NAME_OF_RULE Header-Name =~ /pattern/modifiers
           Specify a rule.  "NAME_OF_RULE" is the name of the rule to be used, "Header-Name" is
           the name of the MIME header to check, and "/pattern/modifiers" is the Perl regular
           expression to match against this.

           Note that in a message of multiple parts, each header will be checked against the
           pattern separately.  In other words, if multiple parts have a 'Content-Type' header,
           each header's value will be tested individually as a separate string.

           Header names are considered case-insensitive.

           The header values are normally cleaned up a little; for example, whitespace around the
           newline character in "folded" headers will be replaced with a single space.  Append
           ":raw" to the header name to retrieve the raw, undecoded value, including pristine
           whitespace, instead.

       tflags NAME_OF_RULE range=x-y
           Match only from specific MIME parts, indexed in the order they are parsed.  Part 1 =
           main message headers. Part 2 = next part etc.

            range=1    (match only main headers, not any subparts)
            range=2-   (match any subparts, but not the main headers)
            range=-3   (match only first three parts, including main headers)
            range=2-3  (match only first two subparts)

       tflags NAME_OF_RULE concat
           Concatenate all headers from all mime parts (possible range applied) into a single
           string for matching.  This allows matching headers across multiple parts with single
           regex.  Normally pattern is tested individually for different mime parts.