Strange errors

[Max Kipness]

After attempting to rsync the /var/spool/mail folder on a sendmail
server, I got the following errors on some of the folders:

chown var/spool/mail/********@*******.com : Operation not permitted
chown var/spool/mail/********@*******.com  : Operation not permitted
chown var/spool/mail/********@*******.com  : Operation not permitted
chown var/spool/mail/********@*******.com  : Operation not permitted

Number 1, what is  it trying to do?
Number 2, is this harmful in any way?
Number 3, how do I get this to work? Rsync stopped shortly after this
with errors.

I'm trying to backup sendmail mail spools.

Thanks,
Max