qmail on debian to qmail on freebsd

[Sollunga S]

Hi all 

Greetings to all, this is my first time installation of freebsd, i am going to use this installation for my mail server obviously qmail+ldap. I have a bit of fear to go ahead on it, can anyone clarify please?

Previous Qmail installation is on debian 3.x and the installation is based on http://www.shupp.org/toaster/,

Now i want to move to a better hardware and ofcourse updated user friendly and uptodate OS. here i opted for freebsd and qmail 1.03 along with this i want to meet users addressbook issue, so i thought of going behind ldap and mysql, (guide me if i am wrong). My doubts are earlier the Mailbox and the cleartext vpasswd are bit scaring me, so i would like to use mysql in place without disturbing any of the users mail addresses, ( i have close to 32gb of data's in mailbox's and some mailing list+forwards). also would like to procure password change option securely. How can i make this migration smoothly with the help of freebsd?

please