[Mailman-Users] users in multiple lists

[Mark Sapiro]

David LEROUX wrote:
>
>I'm a new mailman administrator, first time using it and wondering a few 
>things.
>First one is that we manage a bunch of lists, in which same users may be 
>in different one
>The result is if we send mails to, for example, three different lists 
>with a common user in those lists, this user receive 3 mails, normal...
>But I wonder if there's a way to make that this user receive the mail 
>only once.


If your Mailman is 2.1.10 or later, you can use the Non-digest options
-> regular_exclude_lists option to at least partially accomplish this.

With two lists, say lista and listb this is straightforward. You put
listb at example.com in lista's regular_exclude_lists. Then any post
which is addressed to both lista and listb will be delivered from
listb to all its members and from lista to only those lista members
who aren't listb members.

You could also do it the other way around, but do not put both
listb at example.com in lista's regular_exclude_lists and
lista at example.com in listb's regular_exclude_lists. If you do, members
of both lists will not receive any posts addressed to both lists.

Thus, it gets tricky with three or more lists. Say you have lista,
listb and listc. If you put listb at example.com and listc at example.com in
lista's regular_exclude_lists, and listc at example.com in listb's
regular_exclude_lists, then a post addressed to all three lists will
be sent from listc to all its members, from listb to those members who
aren't members of listc, and from lista to those members who aren't
members of listb or listc, and this works so everyone receives just
one copy. Likewise, if a post is addressed to just lista and listb, it
will be sent from listb to all its members and from lista to its
members who aren't members of listb, and again, every member of lista
and listb receives just one copy.

I think this generalizes to any number of lists, but you need to be
carful how you set it up because if you have even one pair of lists
that are mutually in each other's regular_exclude_lists, then members
of both those lists will not receive a post addressed to both lists
from either list.

Also, this affects only regular delivery, not digest delivery. Digests
always contain all list posts.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan