unable to patch postfix

[magicalshashank31]

I am trying Apply Quota Patch To Postfix i have build postfix.spec file in SPEC folder but when i used to build the spec file :
# rpmbuild -ba postfix.spec

libdb-devel is needed by postfix-2:2.9.2-2.el6.x86_64
systemd-units is needed by postfix-2:2.9.2-2.el6.x86_64

i am unable to install these packages via yum, i have removed db4-devel rpm because libdb-devel conflicts with db4-devel .
but i am unable to install libdb-devel and systemd-units.

i use :
yum install libdb-devel systemd-units.
it says no package found


I am using local repository and epel repository , i have installed all Development tools but unable to install Development libraries at starting.

please help how to install both the packages.

I am following http://www.howtoforge.com/virtual-us...dora-17-x86_64.

To build a mail server.