Last fall the TEI community arranged to have TEI-L archived at 
http://n5.nabble.com/archive-your-mailing-list.html .  It's a commercial 
services but fits the LOCKSS model (not officially but as a concept). 
Nabble archives as of the date you set up archiving through them, but 
they can also ingest your archive in mbox format.  But do watch out for 
handling of character sets when using this format.

It took a while to reach someone at Markmail ( http://markmail.org/ ) 
but apparently we eventually did and now have an archive there as well.

Kevin

On 2:59 PM, Nathan Tallman wrote:
> Dear Lists,
>
> Has anyone worked on preserving a Listserv (proprietary) archive of
> messages? What can one do, other than make sure that the server hosting the
> list in question is backed up (LOCKSS style, with geographic separation) and
> kept up in good working order? The archive search interface does a pretty
> good job at access, but what about true long-term preservation?
>
> Any advice appreciated! Apologies for cross-postings.
>
> Thanks,
> Nathan
>
> ----
> Nathan Tallman
> Associate Archivist
> American Jewish Archives