[Mailman-Users] query re "message has implicit destination"

[Bretton Vine]

Dragon said the following on 2006/08/30 10:03 PM:
> Oops... forgot to send my reply to the list too. Sorry about that 
> Bretton, I did not mean for you to receive it twice.

Not a problem, and thanks for the reply ;-)
However it doesn't solve my problem of determining why a
 TO: list at vdomain; CC: third at party
resulted in "message has implicit destination error".
I can't seem to reproduce the incident myself for some reason.

> I think that the answer is quite simply that it was a design decision 
> made based upon what the designers thought would be desirable for 
> most users.

(no criticism intended to developers, but I have to ask:)
Was this requested by users; were users involved in this decision; or was it
a case of developers deciding for users what they thought was best given the
environment of email/lists from the developer perspective?

I repeat, no criticism intended, I just need to be able to give a complete
answer and am anticipating the questions I'll be asked. :-)

> Personally, I believe it to be a reasonable default.

I don't disagree. However the documentation is clear that BCC'ing a list
will result in administrative oversight (if setting is'on'). But not very
clear as to why a TO:list;CC:3rd-party would result in the same by a post
from a list member who is authorised to post.

In terms of the logs, the error is /exactly/ the same whether it's

 TO: list
 CC: someone

or

 TO: list
 BCC: someone

or

 TO: someone
 BCC: list

Yes, I'm being pedantic -- but an explanation of the principle doesn't
always answer what happens in practice. I know answers can't be sucked out
of thin-air, but perhaps this has come up before?
(or not and I need to look deeper)

> Of course, there is absolutely nothing stopping you from turning the 
> setting off. You probably would want some pretty aggressive anti-spam 
> filtering and possibly graylisting enabled on your incoming queue of 
> your MTA if you do that.

We've found relatively little spam making it to any lists as it is. By just
how much a margin will turning the setting off impact on posts from
non-members reaching the list is non-member posting is already disallowed?
Is it just theoretical, negligible or will have it have major impact?

In terms of our logs, the "message has implicit destination" occurs maybe
once for every 50 or so "post by non-member/unapproved-address to
member-only list" so if you look at it from a higher level service provider
approach it doesn't seem like it would make much of a difference, and
therefore is unnecessary to leave the setting enabled.

I don't quite agree, but it seems to be a point of view without a strong
counter-argument.

regards
-- 
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