CentOS

I"m being pressured to install a newer version of postfix (V 2.3 +) that is currently installed in Centos 7 (V 2.1), to enable custom error messages. I'm loath to install an RPM that is newer than the version supplied from the standard Centos Distribution, as I'm not sure what that would break. Am I being paranoid, or is this a reasonable thing to do ?

Thanks !

No you're not being paranoid and the "best" version is the one that we ship as it gets regular security updates from Redhat.

However, if you actually require functionality that's in newer versions and has not been backported by Redhat then you either need to find a different way to accomplish the same thing or you need to update. The Ghettoforge third party yum repo has newer copies of postfix in their "extras" repo which is disabled by default when you install their ghettoforge-release package (since it replaces the distro copy).