I have entered 127.0.0.1 in Mail server, CF admin. But I'm still getting the ''No SMTP server"

Rick, while that can be a helpful question for some problems, I doubt it's going to help here. The message is not saying the smtp server value is failing to verify or be reachable: it's saying no smtp server has been set in the cf admin.

So Vishnu, you're saying you visit your cf admin mail page, and the value is there? If so, the cf admin you're looking at seems not to be the one controlling the code you're running.

Put a test cfm page into the wwwroot folder under the instance where this admin is, and do the cfmail in there, then call that page with the same values as the cf admin url, such as http://localhost:8500/mailtest.cfm, to run a file of that name in the default cfusion/wwwroot folder. What happens then?

If it works there, what's the url for the test page of yours that was failing?