On Thu, Dec 18, 2014 at 08:53:03AM +0000, John Long wrote: > In the ongoing battle against spammers the latest trick is them not > including a message-id header at all. > > Is there a recipe for Mutt to detect this and score accordingly? Going over > the doc and searching the web I haven't had any luck finding any discussion > on this.
Many MTAs will add one if it's not present (in Postfix, this is determined by $always_add_missing_headers). >From a quick test, it looks like the simple pattern: !~h message-id will do what you want. I tested with 'limit', but you should be able to use this in scores also. Alternatively, if you use a mail filtering tool like procmail or sieve, you can do some stuff to handle it in there (e.g., adding an X-Missing-Message-ID: 1 header if the message-id is missing). SpamAssassin probably already has a rule for this, so if you're using this and can control your preferences, you could also increase the score for that rule. w
