Here is the way to play with sub-list in Sympa. Let’s say create a list named aaa with a sub-list named bbb. Sympa allows to include some list in a particular list. The inclusion is really different from adding firstname.lastname@example.org email to subscriber list email@example.com. Using the list administration module in section Edit list config / datasource you can define as many list inclusions as needed (by default this can be edited only by listmaster).
If including list bbb in list aaa, any subscriber of list bbb is added to list aaa. Of course future changes in list bbb (subscribtion and unsubscription) are automatically reported in list aaa. Some subscriber may be already subscriber of list aaa (because list aaa is open to subscription or because it includes thoses other list), they will not receive messages twice!
Now subscribers of list bbb can see aaa in there subscription list (“Your lists”). Any privilege depending on list aaa member ship is respected. Example, if list aaa archives are private, list bbb subscribers can browse them. Subscribers can change there subscription option for list aaa. Bounce managment is also performed in list aaa for subscribers of list bbb.
The only restriction is that subscribers from list bbb can’t unsubscribe from list aaa, but of course they can choose the nomail option and if they unsubscribe from list bbb they will desapear from list aaa. When browsing aaa subscribers list, the list owner can see the originating data source for each subscriber.
It is also possible to include remote lists coming from some other Sympa server. Many other datasources are recognized by Sympa (SQL, LDAP, HTTP, …) and this contributes to open mailing list definition and features.
Sub-lists are used with non Sympa mailing software just because their auhtorization is based solely on list subscription.
When using Sympa, you may prefer to define a scenario that define authorization for subscribers of some other list.
In other words: Do not include list B in list A if you just want to make list A’s archives accessible to list B subscribers. Modify a scenario instead.