Author: Michael Haardt Date: To: exim-dev Subject: Re: [exim-dev] Adding RFC 2822 date parsing code
> I've found such a measure useful for spam filtering. I implemented something > similar using ${perl. I found that an incomplete parser (only looking for a
> few commonly-used combinations of formats of the many that rfc2822 allows) was
> good enough, for my use. i.e. I never saw any non-spam email use particularly
> exotic formats.
Actually, date-time from RFC 2822 is not that complicated once you look
at the required obsoleted grammar parts.
Indeed some spammers use entirely wrong dates, but most don't. I was
mostly looking into enhancing the formal quality of submissions, but
catching a few dumb spammers is a nice side effect.
> I would suggest that an absolute seconds-since-epoch would be more useful than
> a difference-from-now value.
Just curious: Why? It's no problem really, because you can subtract it
from $tod in ACLs, as you could add $tod to an age. Which application
of an absolute value do you have in mind?
> As for whether/how to implement this within Exim, though, I couldn't say :-/
An implementation inside Exim is a vital part of being able to parse
"Received:" fields. Any votes now? ;)