It is likely to require direct interventions on the Majordomo code. Membership parameters Sympa lets you choose how to define the members for a list. As any list manager, the list can be defined using subscribe and add commands. In addition Sympa allows a list member definition to be a dynamic inclusion of e-mails from various sources. These are clean inclusion in opposition with dirty subscription using a third list to subscribe one to another one.
Every list is defined by subscriptions.
The list can be setup to inform owners of membership or membership removal requests. This solution allows automatic list creation or update. The choice of Majordomo would be an excellent one if messages not complying with its syntax were sent to the list manager address instead of being rejected as being syntactically incorrect. Sympa does not directly manage this address, designed to receive error reports. A contributed software makes it possible to keep, analyze, classify and present them through a web interface for ease of management of these undelivery reports.