Hi Ratnakar,
There is a paremeter in config.tcl which you can use to redirect all mails to your id. Sorry, but I can't remember what it is.
You can also try this -
Go to Control Panel, open Main Site parameters.
Edit EmailRegistrationConfirmationToUserP
RegistrationProvidesRandomPasswordP.
This is how I copied the passwords -
I first uploaded the users, then created another table users2 from the cvs file. This contains the email id, password and salt.
Then I copied the password and salt from users2 to users table.
Hope this helps
Nitish