[CentOS] looking for repositories..

Please, Where can I find a list of repositories all over internet.. I
want to keep my CentOS servers up 2 date with mailscanner, clamAV,
syslog-ng, and others... I know dag has a very goog one but there are
some paktes I can not find in dag repository like mailscanner,
syslog-ng, among others...

Sorry if it's offtopic but I need it!

Thanks in advance

Regards,
israel