Inbox backup :(

I upgraded my server from Mandrake 9.2 (Imapd , postfix & SQ mail) to Fedora
core 2 (dovecot, postfix & SQ mail)
i backed up /etc/passwd , /etc/shadow files & all home directories of users
account on my server ..
after resotration & configuration of the servers everything seems to work ,
except users email they had on the server saved :(
man this is embaracing .. can u tell me wat i did wrong ? where were the
mails stored .. & wat is the right way to do it ?


thanks