recreate mail retrieved as POP

[brian]

I have a client who, in an attempt to upgrade the Thunderbird client, 
had been having some trouble connecting to the server. I responded with 
the connection settings needed and received a reply that the problem was 
that the acct. had been set up as POP. After receiving my mail, the 
acct. was deleted and recreated again, using IMAP, etc. Of course, now 
the mailbox is empty on the server.

So, in the interest of due diligence, is there any way to retrieve those 
messages somewhere on the server? ATM, i believe the client's box is 
WinXP, so if anyone has any clues as to dealing with it from that end 
i'd like to hear them, also.

No, i have no idea why upgrading the mail client required *any* changes 
to the user's setup.

brian