It's quite simple, given the above information from forum users:
if you use pop3 , change the incoming mail server to "mail.ukfreeisp.co.uk" for each email address.
It worked for me, nothing else needed to change, and I was able (as of today 12th July 2013) to download all the emails from uko2.
Remember when you're complaining about uko2, nothing comes for free, we've all been living off someone else's financial input as the demand for non broadband phone connections reduces with the rise of mobile emails and cable and wifi. I offered to pay for the service some time ago as I wasn't using the phone connection. While the person responding from uko2 answered the technical query, they didn't take up my offer of an annual fee for their email provision. It sounds like uko2 was being run by an overgenerous individual, let's hope 'ukfreeisp' manages to survive the Virgins and BTs and TalkTalks, etc, providing something for those who avoid the conglomerates.