Hi Rajani,
It sounds as if your host had a cgi-wrapper running at one point but disabled it, or vise-vera. The only thing that I can think of is to ask your host to chown all the files & directories to user 'nobody' if they no longer use a cgi-wrapper or change them all to the proper user if they do use a cgi-wrapper.
In most cases, the olny user that can chown files and directories is root. That means that it isn't GMail that changed ownership on the files and dirs.
You should be able to delete files and dirs owned by 'nodody' with fileman (as long as you're not using a cgi-wrapper) and files owned by the normal user with a FTP client.
This probably isn't the answer you were hoping for but I hope it helps.
Regards,
Charlie