I am new to Linux and mail server configurations, My company is already running Lotus Domino 7 and sametime limited version on RHEL4 with some users, now our company has planned to go with Zimbra open-source server for some users. They also need to have push mail technology and chating.

My Requests are :

1. If there are totally 20 users, in that 10 users will be in Lotus and another 10 will be in Zimbra, all of these users must be communicated internally.

2. Global Address book must be there for all these 20 users.

3. Best open-source for Push mail technology for zimbra and as well as for Lotusdomino7.

4.All these 20 users must have the same domain i.e., lotus mail users will end up with aaa@xyz.com and zimbra users also endup with bbb@xyz.com

5.Zimbra mails must be traveled through Lotus domino server.i.e., External mails form zimbra must be forwarded through Lotus domino server.

I have Installed zimbra open source mail server on RHEL 5 with the help of the documentation available with zimbra, and now i need to configure all the above settings. please help me in this regard.

Surendra M