Comment 2 for bug 588411

This feature is challenging to build because the mailman-mhonarc list server is separate from the launchpad webapp. Mailman polls Lp for work or asks list/membership via XMLRPC. Extending the current architecture requires:
* A means to store a request for an archive (usually a db table)
* A new launchpad MailmanXMLRPC method to queries the archive table for work.
* A new launchpad MailmanXMLRPC method to send archives to Lp which
  immediately emails it to the requesting user.
* A new mailman XMLRPCQueueRunner method that calls the Lp work method then
  calls the other method to get the archive if the user is a team member.

This is not a good design since the user membership and the list can change between the time of the request and when the request is serviced. I do not think any user really wants 100 MB of mbox data.

A better approach would be get the mbox directly from the list archive server. This could involve hacking the obsolete mhonarc PERL code, but not sane person wants to do that, and no Lp engineer is willing to entertain that.

There is work in progress to finish Mailman 3 and provide a sane archiver <http://db42.wordpress.com/tag/mailman/>. The proposed archiver could be extended to service archive requests.