No, Zimbra doesn't run fetchmail - that's only for users to get mail from ISP (type) accounts and zimbra is a mail server which has mail delivered to port 25.
I'm afraid I haven't used that script to create fetchmail files, as a fugitive from Windows I still prefer GUI type management functions. So, as I mentioned earlier, I use webmin for creating and managing fetchmail accounts - it's much easier, have a look at
www.webmin.com Also, the fetchmailrc file is named .fetchmailrc (a hidden file) and a file is created (in their home directory) for each user that has fetchmail run for them.