(Fwd) Re: [Mailman-Users] Re: [Mailman-Developers] How to rem

[Brad Knowles]

At 12:05 PM -0400 2004/04/04, Bryan Carbonnell wrote:

>  Yes, it may be true that RegExs are foreign to most people (myself
>  included to a certain degree), but wouldn't it make MM more flexible?

	There can be such a thing as "too flexible".  After all, a C 
compiler and a Python interpreter are about as flexible as you can 
get -- so why don't you code your own features in them?

>  And wouldn't it be easier for Barry to implement?

	Maybe.  However, we have to consider more than just the 
implementation cost -- there is also the support cost to consider. 
If it costs 10x or 100x as much to support the regex feature because 
it's too flexible and too confusing to too many people, then it's not 
worth the effort.

>  Do you see my point? If there are an absolutely fixed number of types
>  of headers that could across, then I could see that going your way
>  would work better, but since I can add any header to an outgoing mail
>  that I want, with my e-mail client (like I did with this e-mail),
>  then should the MM admins be given the opportunity to strip them with
>  a RegEx?

	Okay, so a Keep-These-Headers option being restricted to just the 
following:

		From:
		Subject:
		To:
		Cc:
		Date:

	Is not capable of stripping all possible headers that could 
potentially be generated?  Sorry, I don't buy it.


	The only thing that using a regex would do for you that cannot 
easily be done with a strip-these-headers/keep-these-headers option 
is the case of multiple headers which share some subset of their name 
and for which you want the same action to be taken (e.g., strip all 
headers matching "^List.*:").

	I'm just not sure that it would be worth the effort to get this 
relatively small additional functionality, given the potential 
additional support cost that would result.

	But only Barry could really answer this question.

>  Wouldn't safety be to not mess with the mail while passing through
>  MM?

	No, "safety" would be to strip everything that is not known to be 
safe, such as the minimal list of headers shown above.

>  I understand that the RFC are for MTA and MUAs, but shouldn't MM
>  follow them as well? As well as we can anyway?

	Where it makes sense, yes.  But as I said before, a Mailing List 
Manager is effectively a type of gateway system, and while there are 
a small number of documents that describe what are considered to be 
Best Current Practices for MLMs, there are no Required or Recommended 
RFCs that are specifically aimed at them.  As such, you need to apply 
a lot of interpretation when you're looking at RFCs that are written 
for MTAs or MUAs, and try to figure out which parts are applicable to 
MLMs and which ones are not.

>  I'm not trying to argue, just trying to get thing straighened out in
>  my mind.

	This is a point of deep discussion amongst the most experienced 
people in the field.  You are not expected to fully understand all 
the nuances involved.

-- 
Brad Knowles, <brad.knowles at skynet.be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
     -Benjamin Franklin, Historical Review of Pennsylvania.

   SAGE member since 1995.  See <http://www.sage.org/> for more info.