Feature request summary:
That the web admin interface provide the admin (list owner) with a way to download a configuration file for his list which contains absolutely the entire specifics of his list, and a way to upload such a configuration list, so that lists can be backed up or moved from server to server by list owners who do not have system-level access to the Mailman servers, a situation typical of Mailman installs in commercial hosting companies.
Explaination of the Problem and its Context:
There is presently no way for a list owner to extract from Mailman the configurations of his list unless he has command-line access. It is essentially impossible to move a list from one Mailman server to another without data loss unless one has access to the command-line tools and/or the system level files.
Note that manually reconfiguring the list on another server loses all of the bounce-suspensions and user-suspensions (that is, accounts the owners of which have suspended while on vacation). The admin can only suspend subscriptions as "admin", so that, for instance, users on vacation then must ask the admin to unsuspend them. That in addition to the fact that manually configuring all the other user-selectable subscription options for a large list, manually, is an egregiously large task.
In hosted environments in which Mailman is run by the hosting company as a service for their customers -- a substantial share of Mailman list owners are under these circumstances -- it is precisely the situation that the user does not have permissions necessary to run those commands against the server himself. Indeed, he may not be able to log in to the shell on the server at all.
This means he must rely upon the hosting company to run backups of his Mailman configurations; he cannot run them himself to protect against disk failure.
Perhaps more critically, if the list owner wishes to change hosting companies and port his list from one server to another, he has to request a dump of his config at precisely that moment when his hosting company is least motivated to answer his support requests -- after all, he's a lame-duck customer.
Ideally, the administrator's web interface to Mailmail would have at least one, if not two, important new options:
1) A link to a page with downloadable links for each of the config files.
2) A link to a page to submit config files.
I understand #2 is vastly more problematic. Even just having #1, however, would be enormously beneficial, if it just outputs the various files as they appear on the server.