[Mailman-Users] exclude lists question

[Bill Cole]

Mark Prewitt wrote, On 1/6/11 1:54 PM:
> Good Day,
>   I have two lists that have essentially the same members except for one
> person.  Unfortunately, they are client facing lists and we have different
> clients using them so we cannot combine them or eliminate one which would
> make this so much easier.
>
> List a has 5 people on it
> List b has 6 people on it
>
> When we send an email to lista&  listb  many of the people get 2 emails, so
> we put listb in the lista exclude list and lista in the listb exclude list.
> What happened then was surprising, no one got any emails, even the non-duped
> people (as far as I have been able to tell anyway).

This is as documented in the web interface's "details" page for 
regular_exclude_lists:

     Do not specify this list address mutually in the exclude list
     configuration page of the other list, or members of both lists
     won't get any message.

> Anyone have an idea why this would happen and how to resolve it?

This has been raised here before and answered, e.g. the second half of my 
long message at 
http://www.mail-archive.com/mailman-users@python.org/msg57524.html

The setup I described there works, i.e. my regular_exclude_lists settings 
for 4 siblings is like this:

list4: list1, list2, list3
list3: list1, list2
list2: list1
list1: (empty)


This assures that no list excludes a sibling list that excludes it in return.