SpamAssassin Rule: FAKE_REPLY_C
Standard description: none
The mail's subject begins "Re: ", indicating a reply, but does not include the References: header.
(This meta rule currently only triggers if the user agent matches a version known to include a References: header but not an In-Reply-To: header. Other rules originally covered a lack of In-Reply-To: )
The default scores for this rule can be found in the online list of tests.
Details of References: and In-Reply-To: are in RFC 2822 sec 3.6.4