[imp] How to start?

[Kallonen, Jari]

Hi,
I'm planning to replace our old exchance server with Linux based IMP server.
I'm using Linux RH9.0, Apache 1.3.29 and MySQL 4.0.16

What I need (I guess) is:
PHP 
IMAP (c-client??)
HORDE and 
IMP

What versions should I use and how should I configure those?? 

Regards,
Jari