I think I have the Netscape mail-directory from old computer, how do I copy it to new computer?

(Netscape 7.1 Mail, Thunderbird or Seamonkey).

I think I have the files in Olduserbackup\xjuwtwtb.slt\Mail

I create a new mail account with server pop.superuser.com, and find a directory with that name in C:\Users\myusername\AppData\Roaming\Mozilla\Profiles\default\ou6umlif.slt\Mail

I replace the files with those from the backup, but Netscape still shows pop.superuser.com in its interface.

Is there some kind of registry setting somewhere I will have to change?