Thanks for the advise. I try to rsync http://iredmail.org/yum/rpms/ but it encounter the error...
administrator@proxy:~/test$ rsync -avrt rsync://iredmail.org/yum/rpms/ ./
rsync: failed to connect to iredmail.org: Connection timed out (110)
rsync error: error in socket IO (code 10) at clientserver.c(122) [Receiver=3.0.7]
* I have no problem syncing with other ubuntu repo thou...