Sending mail through Gmail

[vivek mahajan]

I have configured James-2.3.2 server  on the system with public IP, I can
log in sucessfully through Java mail api, but can't send or receive mail
from it  using user name user@<public IP> and my code is not showing any
error messsage for sending mail but i can not see it in my database.
I am sending mail by GMAIL to it. PLZ Help