BOAC - thanks for the PM, I'll try that, but in answer to your last .......
......you copy them en block to a 'hold' folder and back that up.
that's what I have consistently failed to do. I can "highlight" a folder - one which I've called "Keep" (!!) but have no option to "send to" or "copy" , but I can open the folder, highlight all the e-mails as one block, then "send as an attachment" .......the whole block, currently around 20 e-mails, which I've done to my Gmail account.
That came in as an option to open each one individually, or send them all to a Gmail folder, i.e. another "keep" folder that I created.
So at least I can back them up on another e-mail system, but again this is a "cloud" i.e. public system that requires Internet access, what I'm looking for is an external storage system that is only between me and my computer, i.e. no Internet involved, as in a cave in Bangalore (should I need to ! ) - to a CD for instance.
Meanwhile I'll try your Google trick - when the grass has been cut, the car washed, the cat flossed etc. etc. ( I wish I had a job, I'd at least get one day off a week ! )