It turns out there is an even easier solution. No fancy downloading is needed.
I have now had a reply from the JISCmail organisers, saying:
> Yes you can absolutely keep archives for closed mailing lists, the process is
> called 'retaining a list'. This is usually preferred over deleting a list,
> which completely removes the list and all its archives.
> When a list is retained no one will be able to post to the list but archives
> will remain available either publicly or privately at your discretion.
That sounds ideal.
Dr G. D. Ritchie
Honorary Senior Research Fellow
Computing Science Tel: (+44) (0)1224 272383
University of Aberdeen Fax: (+44) (0)1224 273422
Aberdeen AB24 3UE
Email username: <FIRSTINITIAL><DOT><SURNAME>
Email domain : abdn.ac.uk
The University of Aberdeen is a charity registered in Scotland, No SC013683.
Tha Oilthigh Obar Dheathain na charthannas clàraichte ann an Alba, Àir. SC013683.