migrate from postfix to qmail

[Lotfi kecir]

HI, thank's for your post.
to give answer to your answer: i rent a dedicated server (Fedora 6) witch
has qmail installed on. and in my old Server witch is in our office turn has
Postfix.
The new sever has as Admin panel Plesk.
I already create all email acounts and now i'm looking to transfert all my
user acount mailboxes.
and i don't have any idea to do it.
Thanks for your help