How to get username and password for sessions that require SMTPAuthentication?

[james_mail]

Hi,
I am developing an  Mail Relay application that uses Server JAMES to do the 
work.

I have a Gmail's account .

I used Mail Client to send a message to JAMES.Then JAMES will relay this 
message to Gmail,but Gmail requires authentication username and password.

How to get username and password from JAMES to relay the mail to Gmail?

Thanks!!!