Here is a sample of what we did.
We have a Groupware app called Memmo
We also have a 512bit encryption chat called memmotalk
We r running Ubuntu 6.10 with Zimbra open edition.

Since the memmo groupware has its own mail client. we were looking for a mail server. We managed to do this.

1) install zimbra
2) install our memmo and memmmotalk so that it uses mysql database along with zimbra.
3) We then only have to install tomcat to run our memmo

Here is a sample

Click on left bar.. memmo to start memmo app
Click on left bart memmotalk to start memmotalk app
username for both is guest/guest
or if you want to try chatting .. you can try tim/tim

Memmo can handle 3 email accounts.. like gmail.
If you want to use zimbra mail.. you will have to use a different password since we do not change any zimbra settings....

Let me know how you like it.
This is just a test site.