My dns lookup (against either of the hosteurope.com nameservers listed for jaa.org.uk) is showing the following for the maui FQDN.
maui.jaa.org.uk. 14400 IN A 213.152.52.233
and I'm getting:
5.29.197.148.in-addr.arpa. 80184 IN PTR adarwash1.ee.port.ac.uk
for the rDNS of 148.197.29.5.
As you can see from the netstat output, cyrus is listening (on all interfaces), but only on ipv6. It doesn't appear to be listening on any interface on ipv4. You do have portreserve "holding" the IMAP ipv4 ports. It's possible that it's not releasing them to cyrus. You may want to look at the man page for that application, and see that it knows about cyrus (mine is only set up to "hold" things for cups).
I would also suggest looking at your yum.log to see if cyrus was updated with the .6->.7 update. If so, look for "rpmnew" or "rpmold" config files. In my experience it is uncommon for updates to move current configs out, unless they are incompatible with a new release (and when they do you should find an "rpmold").
I've never touched cyrus, so can't be of much help trying to (re-)configure it (but I'd look at portreserve first).
Richard - you were right!
It was portreserve !
Many thanks for the advice
John