[CentOS] Postfix 2.6.5 in CentOSplus?

>according to several findings on the web I tried to find postfix-2.6.5 

If you actually need a feature in 2.6.5, Simon Mudd has been releasing them
officially for postfix for ages...

http://www.postfix.org/packages.html Which leads to ->

http://ftp.wl0.org/official/2.6/RPMS-rhel5-x86_64/