Hi Ritu
The mail server host is the name or the IP address of the system hosting the SMTP relay server, so for the configuration use the one which your organization uses to send mails.
After the correct configuration, the mails sent were queued in the server as there is some issue with the server. But, the configuration is correct and it solved the issue which I was facing.
So, please make sure that the host name and port number are correct. That should work fine.
Thanks
Meenakshi