3.5. What is an Umbrella list - and why doesn't it do what I want?

An Umbrella List is a list of other lists.

For example, you have the following lists running in Mailman:

  ThreeBlindMice: Minnie@farm.org, Mighty@cartoon.net, Mickey@disney.com
  ThreeBears: Smokey@usda.gov, Little@pbs.org, Momma@mgoose.net
  ThreeMenNaTub: Rub@tub.org, Dub@tub.org, Little@pbs.org

You can create an Umbrella List called, "Threesomes" and instead of people, it will contain the above list names. When you send email to Threesomes, the message goes to each of the individual lists...

  Threesomes: ThreeBlindMice@mylists.com, ThreeBears@mylists.com, ThreeMenNaTub@mylists.com

When mailman sends out a monthly password reminder, it sends an email to every person in its lists. If it did that for the Umbrella List "Threesomes", then it would treat "ThreeBlindMice" as an ordinary user. Mailman would send an email to "ThreeBlindMice" that contained the password for subscribing or unsubscribing it to the list "ThreeSomes". Everyone on the "ThreeBlindMice" list would receive that message with the password. Now that is fine in the case of Minnie and Mighty, but Mickey has been known to do a few silly things in his time...

You can keep Mickey from getting the password by telling Mailman to send this type of information to "ThreeBlindMice-owner" instead of to "ThreeBlindMice".

By making "Threesomes" into an Umbrella List, you can tell Mailman to add "-owner" to any notices, confirmations and passwords that it sends out to list members.

I would like to see Umbrella Lists do more than just that. IMO, they should only send one message out to each actual user, regardless of how many lists that user is on. Currently, if a message is sent to an Umbrella list and a user is on multiple sub-lists under that Umbrella list, then they will receive multiple copies of the message - one for each of the sub-lists that they are on. In the example above, Little@pbs.org would receive two messages everytime someone sent an email to "Threesomes".

The work-around for this is to setup a script that builds a Mega-list out of other lists on your server.

  #!/bin/bash
  # Create and sync the Pasus_All@mydomain.com mailling list
  # The list includes everyone on a Pasus project mailling list.
  # All the Pasus mailing lists start with the word: pasus
  #
  # create an empty file
  echo " " >/tmp/pasus_list
  #
  # dump out all lists names that contain the word pasus, but
  #   be sure to not include the "_all" list, since that is the list
  #   that we are recreating with this script
  LISTS="`~mailman/bin/list_lists |grep -i pasus | \
    grep -vi _all| awk '{ print $1 }'`"
  #
  for i in "$LISTS"
  do
     # dump all the user emails out to a file for all the pasus lists
     ~mailman/bin/list_members $i >>/tmp/pasus_list
  done
  #
  # this sorts the list and removes duplicate entries
  cat /tmp/pasus_list |sort -u >/tmp/pasus_all_list
  ### the above step is really unnecessary as "sync_members" already
  ### does this automatically - still I like a clean orderly list...
  #
  # feed the list of all pasus users into the "_all" list
  # Note: welcome messages are turned off for this list.
  ~mailman/bin/sync_members -f /tmp/pasus_all_list pasus_all >/dev/null
  #
  # Take only pictures, leave only foot prints...
  rm /tmp/pasus_list
  rm /tmp/pasus_all_list

  # Have cron run this script hourly and the Pasus_all list will be
  # updated automatically every hour.

Thanks to Mark Merlins, Jon Carnes, and Shane Beasley for the above work around.

Note this workaround does not take into account per-member options, especially digest and plain delivery options, and the nomail option. A comprehensive script that does it all can be found at http://www.loowit.net/~james/gen-combined-list

Errata: I just had our sysadmin setup this script for us and he said that to make it actually work he had to remove the quotes from

        for i in "$LISTS"

on line 15. Bill Leuze, systems(at)haven.ca

Also, the preceding lines

  LISTS="`~mailman/bin/list_lists |grep -i pasus | \
    grep -vi _all| awk '{ print $1 }'`"

can be simplified to

  LISTS=`~mailman/bin/list_lists --bare | grep -i pasus | grep -vi _all`

With Mailman 2.1.10 or later, you can use the "sibling lists" feature as a better umbrella list as long as you are not concerned about digest members.

Using the above example, create the list "Threesomes" with no members, and in Threesomes' Non-digest options -> regular_include_lists put

ThreeBlindMice@mylists.com
ThreeBears@mylists.com
ThreeMenNaTub@mylists.com

Then, a post to "Threesomes" will be sent to the regular (nondigest) members of the above three lists without duplication. Note however, that through Mailman 2.1.13 bounce processing won't work in this case for messages sent to the Threesomes list, but starting in 2.1.14, it will.

This is one of many Frequently Asked Questions.