I would like to migrate from qmail to postfix..

-Qmail server runs on ubunto 8.0 version
-Postfix server runs on a redhat 6 VM server (for now due to testing)
- Qmail server uses maildir style format
- Qmail server does not have any aliases setup nor Virtual domains
- Qmail server uses Courier-imap for imap on ports 143 & 993
- Qmail server has 300 mail boxes located under /var/qmail/users
- Qmail e-mail users authenticate using openldap

- I would like to migrate everything running on qmail server to new postfix server if possible.
- I'd like to keep the maildir format
- I'ld like to use dovecot for imap instead of courier-imap
- I'd like to be able to connect to external openldap server.


I am new to mail server stuff and need to be able to do this asap. I need some help, guidance on how I can acomplish this task, maybe some pointers to good and well explained documentation etc. I assume I can use rsync to copy all mailboxes from qmail to new VM and make sure permissions are all the same.

I am not sure as to how to connect to the external ldap server from the new VM. the openldap service runs on the same box as qmail does.

I saw this http://wiki2.dovecot.org/Migration/Courier but I think it would work if doing the conversion on the same box, I wonder if can be done on another server?.