LDAP, Postfix and ispCP???

[drumlover]

Hey there,

I didn't find any advise when I searched so I hope that nobody did open a thread like that, yet...
As I'm setting up my server which is an Debian Lenny 5.x I was wondering if there is any possible help with getting postfix to work with Ldap, and to integrate that into RoundCube webmail.
I don't want all the features of LDAP to integrate with Postfix or ispCP.

What I want is this:
A General Adressbook, that can be accessed from all the users and also one that is Personal to the user.
I want it to work with Postfix, so that I can use LDAP-Clients like Outlook, or Apple Adressbook gain access to it via the Emailadress from the server.
I want it to work with Roundcube Webmail.
I want it to be set up automatically once I create a new user in ispCP.

I know that this is a lot I'm asking for. And I already found out how to integrate an existing LDAP onfiguration with RoundCube.
But about the other stuff.....
Well....
It would be really great if somebody could give me some advise.
I found this package that includes all I'm asking for but I'm a little afraid that it will completely mess up my ispCP-Config
iRedMail

I would be really thankfull for anyone who could give me some advise on that issue...

Kind regards

drumlover