CentOS Errata and Bugfix Advisory 2015:2012 

Upstream details at : https://rhn.redhat.com/errata/RHBA-2015-2012.html

The following updated files have been uploaded and are currently 
syncing to the mirrors: ( sha256sum Filename ) 

i386:
66baa99e68245563bed74404003e8d79b4c4e9e5912c23da24e442489323c4f8  postfix-2.6.6-6.el6_7.1.i686.rpm
5c9eff2ceb39dd89a43b82a85e575dc576aeb4c113e21908290d21f6057277a1  postfix-perl-scripts-2.6.6-6.el6_7.1.i686.rpm

x86_64:
f409038a6cd3a901fd884bcf8145d6f0647f358aff6cd4a349efa634bb574d9d  postfix-2.6.6-6.el6_7.1.x86_64.rpm
952cf16ed4821f4b25d6a399c425de8d5e3a8ef9a0eebf4d76bbbc00c6e2cc0c  postfix-perl-scripts-2.6.6-6.el6_7.1.x86_64.rpm

Source:
f751b9cbe3790b67b630622e6ea361b7cedc9498260b167275d3cd7da6b51227  postfix-2.6.6-6.el6_7.1.src.rpm