On Fri, 31 Jan 2014 21:32:33 +0100 Matus UHLAR - fantomas wrote: > After repeated learning as ham I get BAYES_50 at least for the latter > message, but I still wonder, how exactly does spamassassin identify > messages that do not contain Message-Id?
It never uses Message-Id, it uses a hash of the date header and the top part of the body (and up to the 3.3.x releases the bottom received header).
