Update on the admin auth problem:
After sniffing the network traffic to work out what the hell the transporter suite is attempting to do with the admin account:
* OK [CAPABILITY IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ NAMESPACE UIDPLUS CHILDREN BINARY UNSELECT LANGUAGE XSENDER X-NETSCAPE XSERVERINFO AUTH=PLAIN] testmailstore.kent.ac.uk IMAP4 service (Sun Java(tm) System Messaging Server 6.2-9.02 (built Apr 20 2007))
a0004 CAPABILITY
* CAPABILITY IMAP4 IMAP4rev1 ACL QUOTA LITERAL+ NAMESPACE UIDPLUS CHILDREN BINARY UNSELECT LANGUAGE XSENDER X-NETSCAPE XSERVERINFO AUTH=PLAIN
a0004 OK Completed
a0005 LOGIN "adminaccnt/testuser" "blahblah"
a0005 NO Authentication failed
a0006 LOGOUT
* BYE LOGOUT received
a0006 OK Completed
adminaccnt is the admin user, testuser is the user I'm trying to migrate, blahblah is the password.
I've never seen this format of imap login before and I can't find any reference to it - anyone any ideas?
What I really need is:
LOGIN "adminaccnt" "blahblah"
PROXYAUTH "testuser"
:-(