1. How is this work?
2. Is the installation on webserver easy?
3. Can i retrict the member only from the domain i choose? Let say i provide email with few domains : abc@domain1.com cde@domain2.com, etc. Can i restrict my customer to use only domain1.com and domain2.com ?
4. Can i integrate this with socketmail? so that if anyone who registered through socketmail and get theirname@domain2.com can use their email to login to this messenger and if user want to register through the messenger they register for the email automatically?

thanks

You can download the client creator demo to see how easy the installation is and how the WWIM works. You cannot restrict domains, and you probably cannot use socketmail registration.

So basically the member of this messenger can use any email they like? or they need to register first?

Anyway i tried to install the daemon and got the following error while trying to execute the jar files

java.sql.SQLException: Server configuration denies access to data source
java.lang.NullPointerException

Table were created Okroot@server [/home/xxxx/xxxx]# /usr/jre1.3.1_11/bin/java -jar...............................

is that ok?

Well, they can use any email address they want when they register for an account.

The Java error would seem to indicate the application could not connect to the MySQL server. You can use a MySQL tool to see if it did indeed create the tables but it looks like it did not.