I checked in different major common areas that can be happend.
I checked /opt/SUNWexplo/output to check weather there are explora and also check for coredumps...Messages files... But i couldn't find.
Then i used
root@ser1# du -ah /
This command gave me the size of individual file in that file system. This command shows files in subfolders as well.
Then i found some unusual file growing in /var/spool/mqueue
I think those files generated by SEND mail service. Those mails are not delevering and requeue again and again and growing the size.
What i did was, I deleted all those files and disable the SEND mail service. This can do only if you are not using SEND mail for your mailing.
If there is any other options that we can over come from these option please share......
Thanks and Best Regards.