[Mailman-Developers] suggested improvement for Mailman's bounce processing

[Brad Knowles]

At 10:49 AM +0100 2006-08-09, Ian Eiloart wrote:

>  Rubbish. The codes are numbers.

Right.  But, as I said, the codes aren't going to be sufficient. 
They're going to be misleading in many cases, causing us to make 
inappropriate conclusions based on faulty information.  Therefore, if 
you want to uphold the spirit of what you're asking for, you're going 
to have to look deeper and try to start parsing the actual text of 
the bounce message to try to better understand what the real reason 
was.  And that way lies madness.


Otherwise, RFC-1893 would have been sufficient to answer all possible 
questions about this feature, and all MTA authors and all mail 
systems administrators would have been able to perfectly follow those 
guidelines.  We wouldn't have needed RFC 3463, or the updates from 
RFCs 3886, 4468, etc....

The fact that there was some perceived ambiguity lead to confusion 
and inappropriate implementation, and incompatibility.  Which lead to 
newer RFCs being written on this subject in order to try to clarify 
the situation and hopefully lead to greater compatibility. 
Unfortunately, there's still lots of old code and old installations 
out there, and they are unable or unwilling to upgrade, so now you've 
got all this legacy code you're saddled with, along with all this new 
code as well.

So, if you build your parser to handle exclusively RFC 4468 codes, 
and someone has written or implemented an MTA using codes from 1893 
that they misinterpreted, you're probably going to have a hard time 
figuring out what they meant and why.


Keep in mind that you're not only fighting MTA authors here, but also 
the vast majority of clueless MTA administrators that take a 
recommended configuration from someone else that is likely to be 
wrong and apply it inappropriately at their site, and thus perpetuate 
and worsen the problem far beyond the level of damage that MTA 
authors would ever possibly be capable of -- and MTA authors are 
capable of screwing up a whole lot of stuff.



So, show me a parser that fully understands all possible correct 
interpretations of these RFCs, plus all possible incorrect but likely 
interpretations of these RFCs, and we might have something useful to 
talk about.

-- 
Brad Knowles, <brad at stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

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