Impossible to tell with the text you provided. Look at all of the console output, perhaps there is an error earlier on. If Ant returns a non-zero value then Jenkins will print the "Finished: FAILURE" message. Or perhaps you have a multi-part build and subsequent parts failed to run. Ditto for post-build steps (for example, the mail-ext plugin ran into a problem). You might have to look at the Jenkins logs to track down the root cause.
Punit Jain wrote:but if this is the case, than it should show somewhere on the console that sending email failed.
I would never make that assumption.
Punit wrote:i searched for <the log file> but i was unable to find.
Under the Jenkins installation directory there should be a jobs directory, and a subdirectory for each job, and another subdirectory for job number, there is a log directory there. Example: jenkins/jobs/myjobname/8/log
The warnings are from clearcase, so I have no idea about them.
You might try running Ant with the -v or -d options, that might give you some more information.